Danny Mayor's stunning strike saw off Hartlepool and handed Graham Westley his first win as Preston manager.
The visitors had dominated the match, with James Brown and Anthony Sweeney forcing saves from Thorsten Stuckmann.
Mayor ran at the defence and unleashed a fierce drive into the top corner for North Ends' first shot on target.
In the last minute, Stuckmann denied Colin Nish, Nicky Hunt had an effort cleared off the line, Andy Monkhouse hit the bar and then nodded wide.
The harsh defeat was Hartlepool's first in six games.
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Hartlepool United first team coach Neale Cooper tells BBC Tees:
"We should have had the game killed off by half-time.
"We played a lot of really good stuff, but that's why I'm angry because it's some of the best stuff we've played.
"The passion, the desire, it's a hardworking game we play, but if you don't put the ball in the net then it's all for nothing."