Djokovic said: "It was so close. And one of the best matches I've been involved in. Every time he is in a tough situation, he comes up with so many tremendous shots. When I lost the fourth it was disappointing. I had a lot of opportuinies, but credit to him for fighting. It was a high level of tennis, and I was ready to play five sets today. I'm going to enjoy this victory and I will think tomorrow about the final."
Djokovic into Sunday's final where he will face Andy Murray or Jerzy Janowicz. We have that match coming right up for you as Djokovic signs a few autographs out there. What a match that was. Astonishing stuff.
GAME, SET AND MATCH DJOKOVIC 6-3! Del Potro moves 30-0 clear on the Djokovic serve. Djoker chips an overhead in to close to 15-30 behind after a booming first serve. The second serve is walloped into the net by Del Potro. 30-30. Key point. Del Potro benefits from a net cord as he sweeps the forehand away with the pace taken out of the ball. A break point for Del Potro, but Djoker saves the point before a brutal first serve brings up match point. He seals the win with a backlhand down the line.
BREAK DJOKOVIC 5-3! Some quite magnifcent defensive stuff from Djokovic to keep the ball alive with Del Potro moving all over the place with those thumping forehands. Sensational stuff really. He moves 30-15 clear and Del Potro dumps a backhand into the net to hand Djokovic another two break points. Djoker whacks a forehand long on the first chance from deep. The chance for Del Potro to escape, but the error comes as he knocks the forehand wide when it looked easier to find the target.
DJOKOVIC 4-3 - Djoker showing some marvellous composure to recover from some really disappointing moments out there. Djokovic has converted only two out of 13 break points on the Del Potro serve. But he maintains momentum to lead by the odd game in seven. Games on serve.
3-3 - Djokovic brings up a break point of his own with some trademark pinpoint hitting, but Del Potro shows bravery with the second serve. Djokovic tucks a forehand into the net as the scores reach deuce. Djokovic in control of the rally, but he fails with a little drop shot at the net. Can't really believe he has missed that. But he has. Would you believe it? Djokovic then dumps a forehand into the net from mid-court. Djokovic can't believe he hasn't broken there. A huge escape for Delpo.
DJOKOVIC 3-2 - Del Potro scrambles his way back to 40-30 behind with a superb overhead winner at the net after Djokovic fails to come up with the lob. Del Potro then bashes a backhand winner down the line from a Djokovic service. Stunning response again. And we reach deuce. Djokovic pushes a forehand wide from deep to face a break point. Brilliant effort from Djoker as he follows up a big serve with the winning drive down the line. Tough times, but Djoker gets through it for a 3-2 lead.
2-2 - Del Potro moving up to 42 winners with Djokovic on 71. A comfortable enough hold from the big-hitting Argentine, who continues to ask questions of the Serbian. Djokovic trying to exude an air of calmness at such a key moment in this match.
DJOKOVIC 2-1 - Another Djokovic hold to love. Some fine serving by Djoker at the key time. Del Potro requiring some attention from the medics again. Both men so close the winning line. Who will buckle first? Del Potro with tennis balls in hand.
1-1 - A sort of weird sense of calm descends over Centre Court after the chaotic scenes of earlier on. Del Potro races 40-0 clear only for Djokovic to come roaring back with two straight points to make life interesting at 40-30. Del Potro then pushes one long from deep as the score hits deuce. Dangerous times, but Del Potro clubs away a booming forehand missile to move to advantage. He sees out the game on the next point. Games on serve. 1-1.
DJOKOVIC 1-0 - An immaculate love game from the world number one as the match reaches four hours on court. None of this will bother Andy Murray too much if he can make it through to Sunday's final. Both men striking the ball so cleanly. Over to Del Potro on his service game.
SET DEL POTRO 7-6 (8-6) A brilliant backhand winner from Del Potro brings up the set point. His first of the set. And he devours the Djokovic second serve with a thumping backhand winner to level matters at 2-2. What a recovery this is by Del Potro. Sensational stuff in the sunshine.
6-6 - Del Potro somehow gathers his senses to come back swinging with two marvellous hits at 4-2 down with that clubbing forehand. Djokovic then comes up with a winning overhead to move 5-4 clear despite some wonderful recovery skills by Del Potro. Djokovic sticks away a forehand for a 6-4 lead. And he serves for the match. But Del Potro won't go quietly as he wins a stunning rally to trail 6-5. 24 strokes. And he wins the next one to save another match point with a fabulous series of shots.
6-6 - One thumping forehand winner on the run across court speeds beyond Djokovic. That brings a smile to his face, but that is as good as it will get for him in this game as Djokovic does the necessary to force the fourth set to another breaker.
DEL POTRO 6-5 - A cool and calculated game from Del Potro as he holds to love to leave himself on the cusp of 2-2. But he will need to find the break. And that is going to be easier said than done.
5-5 - No break for Del Potro, but not for the want of trying. A couple of booming forehands from Del Potro. One hits the mark, and the other hits the mark only to be ruled out. Replays showed it was in, but Del Potro doesn't challenge. It is game Djokovic instead of a replayed point at deuce. All square again at 5-5.
DEL POTRO 5-4 - A couple of fabulous returns from Djokovic sees the Serbian move 30-0 to the good only for Del Potro to come waltzing right back with four straight winners to hold serve when he looked in deep trouble. Del Potro determined to leave this all on the court. And is making a fine fist of that doing that at the moment.
BREAK DEL POTRO! 4-4 Del Potro comes roaring back to break back. Looked out on his feet, but somehow the Argentine unearths a thumping array of groundstrokes to hit back immediately. Games back on serve. An amazing shot from Del Potro to secure the break as he clubs a forehand winner into a corner of the court that Djokovic can only dream about.
BREAK DJOKOVIC 4-3 - Djokovic applying the dagger at the key moment as the forehand from deep prompts Del Potro to push his forehand into the net. Two break points for the 2011 champion. But Del Potro staves off the first one with a courageous winning volley as he comes to the net to ease over a Djokovic backhand effort on the run. But a crunching forehand from Djoker is too hot to hand. Del Potro catches the top of the net. May be the key moment in this match.
3-3 - Another game goes past, another hold for Djokovic. Reaching crucial moments now for Del Potro's future health in this match. Whatever that future holds, it can't include a dropped service game now. Djokovic up to 52 winners in this match. Del Potro with only 29. Who is looking more tired out there? Could come down to a matter of fatigue.
DEL POTRO 3-2 - Del Potro calms himself down at the key moment leading 40-30. Djokovic racing from side to side to keep himself active in the point. But a crushing sledgehammer of a forehand is more than good enough to sail past Djokovic. Delpo leads by the odd game in five. Impressive stuff from the former US Open champion.
2-2 - Some fine, fine serving by Djokovic under duress. An ace out wide with top spin sees him hold to 15 and gives him another chance to attack the Delpo service game.
DEL POTRO 2-1 - Del Potro races out into a 2-1 lead as three straight points carry him 40-0 clear. A slightly dodgy forehand enables Djoker to claw his way back to 40-30, but Djoker can't wallop the ball over the net for a winner. A solid enough hold for the big Argentine.
1-1 - Del Potro can't turn a high backhand back into the court trailing 40-30. Djokovic levels matters at 1-1. A lovely forehand from Djokovic shows his class continues to endure. We are on serve.
DEL POTRO 1-0 - Del Potro serving after Djokovic departed the scene for a few minutes. Del Potro gets lucky as a forehand just creeps over the line from the baseline via the net. That gives him the platform to scramble over the line in the first game of the fourth set. Timely, timely hold. Can't afford to shed his service game at this stage.
SET DJOKOVIC 7-6 (7-2) First five points go on serve as Djokovic cuts out an attempt at a passing shot by Delpo. A huge error by Del Potro as he misses an overhead with Djokovic grounded. An awful mistake. And the first mini-break goes to Djoker in the tie-break. And the second goes to the Serbian as Del Potro clips a forehand into the net from the baseline. Suddenly errors flying off the Delpo racket as another forehand clips the net. Djokovic converts on the first of his set points. 2-1.
6-6 - Delpo saves three set points! Djokovic comes up with the key play at the big moments as his ball striking bamboozles Del Potro to carve out three set points. Misses the first one by inches, a backhand bullet flies long by inches. Del Potro then comes to the net to convert a volley after Djoker failed with a poor attempt at lob. A blistering forehand winner from the baseline measuring 90 mph is enough to force deuce. Djokovic can't return a big first serve and seconds later he is long. 6-6.
DJOKOVIC 6-5 - A routine hold for Djoker in the context of this match as he tucks away an overhead to see off the game for a 6-5 lead. Breathtaking stuff from both men, but a hold for Djoker at this stage is like money in the bank. Del Potro serves to force the breaker. Huge moments.
5-5 - Two mistakes early in the game by Del Potro are followed by three magnificent points that Djokovic can't seem to fathom. Quite stunning powers of recovery from Delpo because Djoker is not exactly standing like a scarecrow out there. Djoker can't handle a thumping Delpo first serve, and the score will be 5-5. Games on serve. What has Djokovic got in reponse?
DJOKOVIC 5-4 - The world number having to come up with some of his very best tennis, but he is finding a way to keep his nose ahead in this engrossing third set. Pressure really on Del Potro here as he tries to stay alive in this set.
4-4 - Neither man looks like slipping quietly into the night. Real gladitorial stuff as we approach the business end of this crucial third set. Delpo finding his range with a gorgeous drop shot that even the great Djoker couldn't fish out of the middle of the court. Super, super stuff. Remember Murray up after this one. Supposed to be 4pm, but could be some time yet before the Scotsman makes his entrance.
DJOKOVIC 4-3 - Some wonderful stuff from Delpo. Brings up two break points. Golden chance to get the job done on two points. But he can't convert a winning volley at the net before the backhand attempt down the line sails a couple of inches wides. So unfortunate. Djokovic produces an ace down the T for advantage, but Delpo then crackles a backhand winner away to bring matters back to deuce. Pressure on, but the world number dodges a bullet. Again. Phew! Tough one to call this.
3-3 - Delpo blasts a forehand into the net from deep holding a 30-0 lead. He then can't control a forehand on the run as he clips an attempted winner across court straight into the rigging. Some magical hitting is rounded off with Delpo blasting a forehand winner across court that Djokovic can only admire. The score reaches deuce, but Delpo once again comes up with the goods. Djoker missing plenty of makeable shots due to the pressure he finds himself under out there.
DJOKOVIC 3-2 - Djokovic forced to escape a break point on advantage as he comes up with a well-placed serve out wide that Delpo can't return. An ace enough to steer Djoker to advantage before Delpo slides a backhand into the net. A huge game for Djokovic to escape from. Some big serving when it was most needed.
2-2 - A love game from Del Potro is completed with a two-handed backhand winner that is swept away down the line. Utterly magnificent stuff it must be said from the big Argentine, who is warming to this task the longer this match cracks on. No signs of knee distress.
DJOKOVIC 2-1 - Del Potro seems to be letting it all hang out. Very dangerous at the moment. And Djoker is a man under pressure. Djoker quickly races 40-0 clear before Del Potro hits back with two points of his own. Djoker drops the next two points, but Del Potro can't force deuce as a ball trickles into the net. We remain on serve.
1-1 - Djokovic with 28 winners compared to 15 from Del Potro, but he can't make the breakthrough on the Del Potro serve as the Argentine brings matters level at 1-1 in the third set. Del Potro holding firm on the baseline. Which is a good place to hold firm from.
DJOKOVIC 1-0 - It has been 11 hours and 22 minutes since Djokovic dropped a set. How will he deal with this one. Well, quite nicely in that game as he drops only one point on his way to opening this set with a comfortable hold. Decent flick down the line with the forehand to finish off the business at hand.
SET DEL POTRO 6-4 - A brilliant move from Del Potro as he scampers to the net to chip over a lovely little winning volley and bring up three set points. Djokovic can't return a booming serve seconds later. This match heading for a third set. Del Potro well and truly inspired. Fabulous, swashbuckling stuff from Del Potro.
DEL POTRO 5-4 - Djokovic keeps the man from Argentina honest with a hold to love. Del Potro now forced to come up with a hold of his own to bring this contest level at one set all. An air of expectation governing the mood of this match and then some.
DEL POTRO 5-3 - They say it is not a break until you hold your own serve. Del Potro races out to 40-0 only for a forehand into the net and a double fault to hold up his progress. He then clips a forehand into the net on the run as the score reaches deuce. Key moments now. Del Potro faces a break back point after missing from the baseline, but he punches away a couple of forehands from mid-court to move to advantage. Djokovic is long with a forehand seconds later. Brilliant hold.
BREAK DEL POTRO! 4-3 - A break to love by Del Potro, who is suddenly leaping around that court like he has won the title. Some magical play by Del Potro, who has the bit between his teeth. This is fabulous stuff from Del Potro, who is an inspired figure at the moment. Two games short of levelling this match at one set all.
3-3 - Del Potro forced to save a break point with just his second ace of the match. A blistering backhand from near the net gives Del Potro advantage after another booming first serve. Del Potro tries the passing shot, but Djoker converts the volley across court to bring the score back to deuce. Del Potro is long from deep seconds later and there is another break point for Djoker. But this time a mishit from Djokovic lets Del Potro off the hook during a rally. Del Potro wobbling, but escapes.
DJOKOVIC 3-2 - Another game flies by with Djoker dropping only a solitary point. And breathe. A doctor arrives to slam a couple of pain killers into the paws of Del Potro. And we continue with this second set. No breaks of serve so far.
2-2 - A love game from Del Potro. Couldn't have timed that better if he tried to. A rare serve to love, but Del Potro will take any moments of slackness from Djokovic that are going. Which are not many at the current time. Djokovic wins matches 438 times to 22 when he carries off the first set. Ominous for Del Potro.
DJOKOVIC 2-1 - This set following the same pattern as the first set. Djoker gets a bit lucky with a net chord, but he was well on his way to the game by that stage. Umbrellas out on Centre Court, and there is plenty of chatter among the patrons. Former Wimbledon champion Stefan Edberg watching this match in the cheap seats. Vital that Del Potro keeps pace with Djoker here.
1-1 - Solid response from Del Potro as he levels at 1-1. A bit down after dropping serve at the key moment in the first set, but keeps his head together well to bring matters back on an even keel early on here. Del Potro well down on winners so far with Djokovic hitting 16 crunching winners compared to only six by Del Potro.
DJOKOVIC 1-0 - Djokovic really warming to this match on a boiling hot day as he clips a forehand down the line to finish off the opening game of the set by shedding only one point. Djoker is a brilliant front runner. These are dangerous moments for Del Potro one suspects with his knee problems.
SET DJOKOVIC 7-5 - A quite magnificent drop shot from Djokovic is too good for Del Potro after a breathtaking rally. Real strain on Del Potro with the score at 30-30, and that increases as a ball from deep drops long. Del Potro forced to face the set point, but he can't do the business as a forehand spins wide after the second serve. Del Potro loses his first set of these championships. Djokovic comes roaring back from trailing 30-0. Quite magical play from the Serbian.
DJOKOVIC 6-5 - Del Potro failing to come up with those booming groundstrokes that were fizzing away from David Ferrer the other day. Falls 40-15 behind down and his angst is obvious as an attempt at a lob drops out of the court and long. Suddenly Del Potro will be forced to to hold serve to restore parity in this first set at 6-6 and force the breaker.
5-5 - Another chance for Djokovic at 30-30 on the Del Potro serve as he cracks a forehand into the net down the line when he looked certain to be moving to a set point on the Argentine's serve. Del Potro puts away a winner down the line with a brutal forehand seconds later. 45 minutes gone. No breaks of serve.
DJOKOVIC 5-4 - Djoker carries himself 40-0 clear before a missed backghand and forehand present Del Potro with an unlikely chance. Djoker then comes up with a kick serve to cement the hold. Del Petro will suddenly serve to remain in this set trailing 5-4. Will Djoker make his move here?
4-4 - Superb winning lob volley from Djokovic carries him back to 30-30, but another Djokovic error on the backhand side that drops wide presents Del Potro with a game point. Another rally ends with Djokovic slamming a backhand into the net. This match suddenly level late in the opening set at 4-4. All to play for, and then some. Djokovic with nine unforced errors compared to five from Del Potro.
DJOKOVIC 4-3 - Del Potro presented with half a chance to bring up a break point at 30-30, but he just can't convert a forehand winner on the run under pressure from deep. A big first serve from Djokovic drops out of the court on the return from Del Potro, and Djokovic heads back to his chair punching the air. No breaks of serve as yet, but Djokovic leads by the odd game in seven.
3-3 - An epic game. Del Potro warming up nicely with a serve of 130 mph carrying him 30-15 clear, but Djokovic picks up the next two points as Del Potro fails to see a ball drop in at the baseline. Del Potro facing a break point, but he rescues the situation with a well-placed first serve that Djoker can't return. Djokovic slams a forehand wide out of court seconds later before Del Potro finally gets over the line after several punishing points. Big hold for Del Potro at a key time.
DJOKOVIC 3-2 - A bit more of the same as Djokovic finalises the first two points of this fifth game. Del Potro prompts an error from the world number one, who then comes roaring back with a booming forehand winner from deep. Del Potro can't return a serve seconds later and we remain on serve with the Djoker ahead by the odd game in five. Time for a cup of tea.
2-2 - Rare sight of Djokovic missing an attempt at a backhand winner. Del Potro marches confidently to 40-0 before Djokovic slams a forehand into the net on the second serve. Chance missed perhaps? 11 minutes gone and we are all square at 2-2. Djoker yet to find rythmn on those returns.
DJOKOVIC 2-1 - A love game from the Serbian, who is seeing those tennis balls like footballs out there. No real chance for Del Potro to get his groundstrokes going as a big one down the T and backhand winner up the line edges the world number one in front.
1-1 - Some fine rallies in that game. Del Potro with an ace down the middle before Djoker dumps a forehand long. Djoker struggling to get a read on that Del Potro serve as another big serve down the middle is enough for Del Potro to level this business up at 1-1. Good serving from both men early on.
DJOKOVIC 1-0 - Djokovic quickly showing off his flashing forehand as he puts away a couple of shortish balls in moving 30-0 clear. The backhand winner from mid-court then carries Djoker 40-0 to the good. Del Porto finally finds some length with a forehand as his opponent dumps one into the net, but an ace from Djokovic finishes matters off. Fine hold in the opening game from Djokovic.
Djokovic to serve in the opening game of the match.
Djokovic takes to Centre Court for his 13th successive semi-final at a Major, while Andy Murray's match-up against Jerzy Janowicz will be his fifth consecutive appearance in the last four at Wimbledon. WIll the big two contest Sunday's final?
Players on their way out. Djokovic leads the head-to-heads 8-3, but that is unlikely to mean much when the action gets started on a scorching Centre Court. What a gorgeous day for tennis.
Good afternoon and welcome to LIVE coverage of Novak Djokovic against Juan Martin del Potro. The sun is shining on Centre Court. This should be an eye-catching encounter. Djokovic starts a warm favourite in the sunshine, but Del Potro managed to eclipse the world number in winning bronze at last year's Olympic Games.