A brace from Leon Cort and a Richard Cresswell goal helped ensure City made it twelve games unbeaten in the Championship.
Former Crystal Palace defender Cort, who joined the Potters for £1.2m this week, headed home in the 16th minute, before Cresswell capitalised on Andy Lonergen's mistake to make it 2-0 before half time.
Preston got back in to the game through Chris Brown, before Cort sealed the win with a towering header in the 72nd minute.
The win lifts the Potters up to third place, just one point behind Bristol City in second.
Manager Tony Pulis made two changes ahead of the match, with Andy Griffin making his first start since returning along with Carl Dickinson's return to left back.
Jon Parkin and Gabriel Zakuani made way for the pair, with Pulis reshuffling the starting line up.
Danny Pugh moved back to the left flank, with Cresswell partnering Ricardo Fuller in attack.
It was the visitors who started the brighter of the two teams, with new signing Chris Brown causing the City rearguard problems.
The former Norwich star almost latched on to a clever Richard Chaplow ball, but Cort got back in time to brilliantly clear the danger.
Ex-City youngster Lewis Neal looked lively down the left flank for Alan Irvine's side, as they continued to take the game to the Potters.
However, with City's first surge in to the opposition's penalty area they took the lead.
Rory Delap's long through was exquisitely flicked on and in to the bottom left hand corner by new £1.2m signing Cort, for his fifth goal of the season.
The goal ignited the Potters as a passage of fluent football followed. Top scorer Fuller, Liam Lawrence and Cresswell passed their way through the North End back line, but Danny Pugh fired just wide.
A howler from visiting keeper Andy Lonergen gifted Cresswell the opportunity to double City's advantage and he duly obliged from three yards, taking his tally for the season to nine.
Just four minutes later City should have been awarded a blatant penalty. Fuller used his pace to burst past Callum Davidson, and the defenders trailing foot tripped the Jamaican, but referee Stuart Attwell waved play on.
The hosts continued to look the more likely to add to their goal tally, and another effort from Pugh went close, before Lonergen gathered Lawrence's in-swinging corner from off the head of Cort right on the half time whistle.
City continued the second half from where they left the first, on top. Another trademark Delap throw in was almost turned in to his own net by Youl Mawene, but Lonergen produced an outstanding save to palm the ball around the post.
Fuller the set about making it three a minute later, but after bursting past three defenders his ball in to the six yard box was cleared away for a corner.
Lawrence's ball in to the box found the impressive Delap, who attempted a spectacular volley which was deflected just past the post by Liam Chilvers.
Preston began to pile some pressure on the Potters following the arrival of Neil Mellor off the substitutes bench, and they managed to halve the deficit in the 68th minute.
Simon Whaley whipped across a dangerous ball which found Neal unmarked at the back post, he headed the ball across goal and Brown beat Shawcross to fire home.
With the North End fans in full voice the Potters soon made them quieten down, by making it three.
Another dangerous corner was fired in by Lawrence, where Cort met the ball with aplomb to head the ball in to the top corner, despite the efforts of Lonergen and Mawene.
Pugh had the chance to grab a goal against his former club late on, but after dancing through the defence his shot was blocked by Lonergen.
