It was Lee Trundle, who has spent most of the season as a £1million misfit following his move from Swansea City, that set them on the way to victory.
The striker, who lost a regular first-team spot back in November, brushed in Michael McIndoe's free-kick in the eighth minute before steering a pass to McIndoe for the winger to smooth in the second goal from a few feet out.
Preston's keeper, Andy Lonergan, had an unhappy time with both goals, especially for the first , which came from a 40-yard free-kick, hotly disputed by the visitors captain, Paul McKenna.
Between City's first two goals, Preston had two clear chances to pull one back. Top scorer Neil Mellor was robbed in the box before he could shoot while Lewis Neal failed to find the target with an unchallenged shot to the left of the box.
Central defenders Sean St Ledger, fit from a hamstring, and Neal Trotman, in only his second game for Preston, rendered City's target figure Dele Adebola redundant.
No-one though could contain 31-year-old Trundle, who was almost arrogant in his second return to form and favour.
Matt Hill and Chris Sedgwick were booked for hauling him down and Sedgwick's foul early in the second half put the game beyond his side.
From just outside the angle of the box on the left side, David Noble bent a superb shot over the wall into the top far corner.
Preston knew they were going down to only their second defeat in 11 games, while City were winning for the second time in the same number.
There should have been another goal for Trundle but, as he sent a casual push towards an empty net, Hill arrived like an express train to clear the ball off the line.
Both managers used their three subs, the last player off was Trundle, who fell into a deep embrace from his very happy boss, Gary Johnson.