Preston left themselves with a mountain to climb as Leeds took the lead on 13 minutes when Kemar Roofe converted a Kalvin Phillips cross.
North End got back on level terms four minutes after the break as Paul Gallagher scored from the penalty spot after Billy Bodin was fouled in the area by Vurnon Anita.
Sean Maguire put Preston in front from a Gallagher cross just three minutes later as the game turned on its head before Alan Browne wrapped up the win with a header eight minutes from time as Preston kept up their play-off charge, ending a run of three straight defeats and now within five points of the play-off spots with four games remaining.
Leeds are now without a win on the road since Boxing Day and slipped down to 14th in the table.
But Whites boss Heckingbottom came away from Deepdale distinctly unhappy with some of referee Lee Probert’s decisions.
“We started brightly in the second half but they scored from one of our attacks,” said Hecklingbottom
“We had players in decent position but Billy Bodin does a stepover and Vurnon Anita brings him down. There didn’t seem to be too many appeals from the lads, so giving a penalty away is a blow. The big turning point in the match is the second goal.
“Pontus Jansson was down and it got stopped for the same incident in the first half. It should have been stopped. We had a man down in the box playing them all onside and giving them a free header.
“The worst thing is how it leaves us, credit to the players who stuck at it but as it stands now that’s all we’ve got - those players are the only ones available.”
Heckingbottom called on the club’s more experienced players to set a leading example between now and the end of the season.
“The senior players have to stand up and help the young players who made their debuts,” added Heckingbottom. “There is a lot of responsibility on some young players who have suddenly become our senior players.
“The fans were exceptional tonight and they have to stick with these boys because they will give them everything. We’ll keep trying to improve. We have to keep working with the players.”