A converted try to centre Travis Robinson with three minutes remaining handed a much-needed win to the lowly Panthers and silenced a crowd of 11,000 at Mt Smart Stadium.
Errors and a tiring defence brought on by more injury bad luck opened the door for Penrith and will keep the fire burning under McClennan for another week.
The first-year coach fended off questions about job security beyond this season - or even this week.
"I'm not sure, I can't really answer that," he said.
"As far as I'm concerned, I'll keep trying to do the best I can for my players. I'll control what I can control."
McClennan said he was involved in talks with Kiwis coach Stephen Kearney on Saturday regarding a possible role at the Warriors but wouldn't reveal any details.
McClennan preferred to focus on what he felt was a gutsy effort by his team after he was forced to go to the interchange bench six times in the first half. One occasion was to replace tackling-machine hooker Nathan Friend, who exited in the 17th minute with a dislocated shoulder.
"I've said to them in the sheds, I'm proud of them," McClennan said.
"To only have four subs in that second half, that's a pretty good effort by the lads."
It was an important result for Penrith coach Ivan Cleary, the former Warriors mentor admitting the game was of a poor standard.
"It looked like two teams who haven't won much this year, that's what that second half looked like," Cleary said.
"Just watching that second half, I thought all we had to do was sort out some of our own issues and we'd get over the line.
"We didn't manage to do that until three minutes to go."
The Panthers were locked with Parramatta in last place coming into the round while the Warriors will remain in 13th thanks to Robinson's late heroics, set up by strong charge from Kiwis prop Sam McKendry.
Following heavy losses to the Sharks and Cowboys, this performance was a return to the Warriors' previous trend of letting leads slip.
They opened the scoring when centre Ben Henry fell on a Carlos Tuimavave grubber and it was 10-0 when halfback Shaun Johnson intercepted an attempted Michael Gordon cut-out pass and raced 80m to touch down.
A period of Panthers pressure resulted in a try to Kevin Kingston three minutes before halftime after five-eighth Lachlan Coote accelerated into space.
Henry's converted try soon after halftime was cancelled out by the dangerous Coote with 20 minutes remaining when he spun out of a poor James Maloney missed tackle.
The Warriors are now one loss away from matching their worst-ever season losing streak of seven, set in 2000.
Gold Coast coach John Cartwright described his side's 24-16 must-win victory over Parramatta at Skilled Park on Sunday as a "wake-up call" as the Titans walk a tightrope towards the NRL finals.
The Titans have moved within striking distance of the top eight but still need to win matches against Penrith and Manly to have any hope of making the top eight.
The home side led 12-0 after 34 minutes and although they did enough in the second half to get the vital two points, it was hardly the performance of a premiership contender.
Missing inspirational prop Luke Bailey, who suffered a season-ending achilles injury in the loss to Melbourne last week, the Titans notched only their fourth home win this season in front of 14,159 fans to move to 24 points on the ladder - two behind eighth-placed Wests Tigers.
Without looking for excuses, Cartwright said the Titans were "lethargic" after putting so much energy into their back-to-back losses to top-four sides South Sydney and the Storm.
"I was a bit disappointed at times but in hindsight it was a dangerous game and we got a victory. We win our next two games and we'll be there (in the finals)," Cartwright said.
"Hopefully that was a bit of a wake-up call for us. You can't be flat, it doesn't matter who you play at the moment, especially us.
"After the first third of the competition, I think we were favourites for the wooden spoon so if we can somehow land ourselves in the eight, it'll be just reward for the players' efforts."
The Titans must have been in a slumber after the halftime break as they ran onto the field with only 12 men before Ashley Harrison belatedly joined the action.
Gold Coast skipper Scott Prince joked at the post-match press conference that the Queensland Origin back-rower must have been busy on the toilet as the kick-off was delayed slightly.
Parramatta's scheming halfback Chris Sandow was put on report for a high shot on fullback Will Zillman, who scored the opening try, and 11 minutes later he gathered a Fuifui Moimoi off-load and ran 50m to cross under the black dot.
Trailing 14-10, the Eels had a sniff of victory but tries to Steve Michaels (59m), despite the hint of an obstruction in the lead-up, and Kevin Gordon (64m), who brilliantly snatched a Prince bomb, took them one step closer to the dreaded wooden spoon held by the Titans.
Both Cartwright and star forward Greg Bird conceded the Titans would have to lift against Penrith at Centrebet Stadium on Saturday night to keep their finals aspirations alive.
"I think mentally we were a little bit down, Cartwright said.
"The way the game was officiated, it didn't allow for an open brand of footy. It was a pretty dour game."
Bird added: "If we want to be competing with the big sides, we have to be consolidating leads like that (12-0) rather than struggling away in the second half.
"I'm happy we got the win but there's a few defensive errors that we spoke about at the start of the week and we just lacked discipline."
And Manly again flexed their NRL premiership muscle in a 42-20 thumping of Newcastle at Brookvale Oval.
The eight tries to four victory was the Sea Eagles fourth win in the row, while the loss has put a big dent in the Knights' hopes of making the NRL top eight.
On the back of a superb first half in attack, Manly led 38-4 at the break and had the game all but won.
A raft of Sea Eagles injuries, and a spirited Knights fightback combined for a second half in which the Knights outscored Manly 16-4, but the ascendancy Manly gained in the first half proved to be too great.
From the moment Knights halfback Tyrone Roberts put the ball out on the full from the kick-off, Manly dominated the contest.
The home side scored two tries in the first six minutes to Jamie Lyon and Glenn Stewart to race out to a 12-0 lead.
Kevin Naiqama hit back for the Knights in the 13th minute, but from there the first half was all Manly as they opened up a 34 point lead at halftime in a highly entertaining display of rugby league which included two tries in 10 minutes to Tony Williams and two tries in four minutes to Brett Stewart.
Williams threw off Jarrod Mullen for his 17th minute try, then Kieran Foran scored after Jamie Buhrer broke through the Knights defence in the 22nd minute.
Canterbury-bound Williams then pounced on a Foran grubber for his second try in the 27th minute.
Stewart then scored from a brilliant 50m scything run in the 32nd for his almost mandatory Brookvale Oval four-pointer, before the fullback crossed again four minutes before halftime - beating the Knights defence close to the line.
The 38-4 scoreline at the break summed up the home side's complete domination.
But injuries severely slowed their momentum in the second stanza. Jason King (shoulder), Matt Ballin (calf) Jamie Buhrer (concussion) and David Williams (leg) left Manly coach Geoff Toovey without an interchange bench to turn to for the last 36 minutes as the NRL defending champions eased to their 14th win of the year.
Naiqama (51st and 63rd minute) and Jarrod Mullen (54th minute) crossed for the visitors as they attempted to make a game of things.
But the deficit proved too great and a 77th minute try to Jorge Tafua gave Manly the 22-point win.
Of further concern for Manly, Tony Williams was put on report for a possible 66th minute trip, and for the Knights Kade Snowden is also on report for a lifting tackle shortly after.