Martin Smith kept his cool to slot in Huddersfield's first penalty of the season to secure the Terriers three priceless points in their desperate battle to beat the drop.
Smith stroked a low shot to keeper Romain Larrieu's right to bag his ninth goal of the season eight minutes from time after Hasney Aljofree handled in the box.
Top scorer Smith could have ensured victory on 87 minutes but blasted wide of the target from an Andy Booth pass.
And the striker could have had a hat-trick, but a devilish first-half free-kick curled from 25 yards smashed off Larrieu's crossbar.
The home side started well and might have grabbed the lead in the first minute when midfielder Dwayne Mattis crossed from the right for the towering Booth. The burly veteran striker was about to head goalwards when Larrieu plucked the ball from him.
The visitors gradually grew in stature and Jason Bent should have helped himself either side of the break, but was left to rue his poor finishing.
Bent volleyed wide on 40 minutes from Ian Stonebridge's left-wing delivery after ghosting behind Town's defence and just after the interval Bent contrived to miss from just two yards out from another Stonebridge cross.
The Pilgrims also had three penalty appeals of their own waved away and boss Paul Sturrock was scathing of referee Eddie Ilderton's performance.
"Everybody thinks we had three good half chance calls for a penalty, but the referee somehow managed to miss them even though he was eagle-eyed enough to spot the handball at the other end," Sturrock said.
"If Bent had scored just after half time it might have been a different story had we gone ahead at that point we might have gone on to win." Meanwhile, Huddersfield's win was overshadowed by their continuing off-field problems. The Terriers are £6million in debt, face possible liquidation and are in breach of their players' contracts having not paid them in full since November.
Club captain Steve Jenkins has already walked out to join promotion chasing Cardiff City, but manager Mick Wadsworth remains philosophical.
"If I worried too much about things like that then I'd probably end up in a mental hospital," Wadsworth said.
"But the main thing is that we got another win under our belts. Ironically we have gone back to the bottom, but we have closed the gap on the teams above us."