With temperatures reaching well over 30 degrees at the outset of the match on Rod Laver Arena, it was Serbia's Djokovic who kept his cool in the key moments as he was broken first by Nadal in the final set only to break his opponent twice in an astonishing contest that ran for five hours and 53 minutes.
The previous longest final was Mats Wilander's win over Ivan Lendl in the 1988 US Open final that ran for four hours and 54 minutes.
It will be recalled as one of the greatest finals the sport has witnessed with neither man willing to wilt in the face of a barrage of baseline bullets.
Djokovic's ability to finally muzzle Nadal's best efforts illustrates why he is his sport's undisputed number one.
It came despite the best intentions of Nadal to make a fight of the final by somehow winning the fourth set 7-5 on a tie-break having seen his game dismantled in the second and third sets by the ferocity of Djokovic's groundstrokes.
Nadal is officially number two in the world, but should take enormous heart from his performance despite losing a seventh straight match to his nemesis.
Djokovic becomes the fifth man to win three straight Grand Slams having throttled Nadal in the Wimbledon and US Open finals last year.
He joins Nadal, Rod Laver, Pete Sampras and Roger Federer as the only men to win three straight majors since the Open era began in 1968. He has snared four out of the past five Grand Slams among his overall haul of five, but this was a close run thing. Much closer than many had predicted beforehand.
Djokovic was pushed to five sets by British number one Andy Murray in the semi-finals on Friday, but showed few signs of sluggishness in beating down Nadal's challenge after losing a fairly mediocre first set.
Nadal had promised to be more aggressive, but seemed to find himself in a state of paralysis as Djokovic went to work on his game with a ruthless efficiency in moving two sets to one up only for Nadal to produce a brand of magic that has been missing in previous matches against Djokovic.
It was little wonder both men needed to sit down on chairs before the presentation ceremony began just before 2am on Monday morning in Melbourne with the roof on Rod Laver closed after a thunderstorm had turned the final into an indoor match with the final delicately poised at 4-4 in the fourth set.
Nadal drew first blood by breaking for a 3-2 lead in the first set only for Djokovic to restore parity at 4-4 aided by untimely errors from his opponent's racket.
With the first set running for one hour and 11 minutes, Djokovic was left looking crestfallen as he knocked a backhand long before Nadal moved one set ahead by snaffling up his third set point.
By their previous high standards, it was hardly a classic. Nadal was one set up, but there remained a gnawing suspicion that Djokovic was beginning to turn the match in his favour. Nadal was bleeding unforced errors in the fourth game of the second set as a couple of misplaced forehands from deep enabled Djokovic to break for a second time in the match to lead 3-1 in the second set.
Nadal broke back to trail 5-4 after a sloppy shot down the line allowed Nadal to convert a winning volley before a double fault condemned Djokovic to his fate as three set points eluded him.
He was not sporting a hangdog look for long as Djokovic got the job done on his fourth set point courtesy of another Nadal double fault with the final now running for two hours and 27 minutes.
It became clear that the match was not going to slip quietly into the night even Nadal seemed destined to lose in four sets as Djokovic broke twice in the third set to move 2-1 ahead with a 6-2 scoreline that left his opponent looking increasingly forlorn.
Nadal's answer was utterly breathtaking despite an inconsistent second serve as he dragged himself from a pit of despair to save three break points at 4-3 down with a couple of majestic serves before the rain came down prompting a 15-minute delay.
Nothing could split the pair who were suddenly finding their peak form approaching the tie-break. Again Djokovic seemed on the cusp of victory leading 5-3 in the breaker only for Nadal to reel off four straight points with his opponent misplacing shots under severe pressure.
The crowd were firmly in the Nadal camp as an unlikely victory beckoned when he broke for a 4-2 lead in the final set, but their groans were palpable as Nadal somehow pushed a backhand wide from the middle of the court for what would have been a crucial 40-15 lead. Despite looking extremely fatigued, Djokovic broke back immediately to trail 4-3.
Nadal saved a break point to move 5-4 clear only for Djokovic to drop one point on his next service game before breaking Nadal at the third time of asking in the 11th game to move 6-5 ahead.
The drama was not yet finished as Nadal brought up a break point to level at 6-6. Djokovic recovered with a trademark winner on the backhand side before a crushing serve gave him the platform to convert a forehand drive to finally end Nadal's resistance.
In the final analysis, Djokovic hits 57 winners to Nadal's 44, but Djokovic's ability to win 63 percent of points on second serve compared to Nadal's 45 percent was perhaps more telling.
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