Republic of Ireland internationals Darragh Lenihan and Alan Browne were botj on the scoresheet at Deepdale, but it was Lenihan's Blackburn that came out on top in a a convincing 4-1 win over their neighbours.
Tony Mowbray’s men strolled to a first away win since mid-January and moved to within three points of sixth-placed Sheffield United with two games remaining.
Impressive Rovers ended their five-match winless run in the Sky Bet Championship in some style while condemning the mid-table hosts to a second straight defeat.
Just when they probably needed it most, Rovers got off to a flying start in their eagerly anticipated Lancashire derby clash.l.
Joe Rothwell had already gone close before Rovers struck twice before 12 minutes had been played.
Sam Gallagher opened the scoring in the ninth minute, diving in superbly to nod home a rebound after Ben Brereton-Diaz’s header had bounced out off a post.
Barely three minutes later, Rovers profited from more disappointing North End defending.
Brereton-Diaz this time touched the ball to midfielder John Buckley, and he was allowed to dart forward before seeing a 20-yard strike fly into the corner via the slightest of deflections off North End defender Andrew Hughes.
The visitors were buoyant, but they ran out of steam somewhat after their early blast, with North End halving the deficit just before the half-hour mark.
Former Rovers man Greg Cunningham passed short to Alan Browne, and the Irishman fired home from 18 yards via another deflection, this time off Scott Wharton.
Cunningham fluffed a decent chance to level it up soon after, and it was becoming much more of an even contest.
However, eight minutes before the break Rovers struck again.
This was a super set-piece effort, with Lenihan leaping smartly to head home Rothwell’s precise free-kick.
After a rather pedestrian start to the second period, it was Rovers who notched again to effectively wrap up victory in the 52nd minute.
Lewis Travis made it four with his first goal in two years, meeting Brereton-Diaz’s pass before turning neatly and lashing home clinically.
North End now looked well out of contention, but they rallied and Rovers’ keeper Thomas Kaminski was twice called into action.
The Belgian saved brilliantly from close range to deny Emil Riis and then got down competently to save Ben Whiteman’s crisp free-kick.
At the other end, Rovers almost bagged a fifth when Brereton-Diaz’s looping header bounced behind off the crossbar.
Preston rarely looked like adding a second goal in the closing stages as the visitors enjoyed a surprisingly routine win against a side who had only lost three previous home fixtures so far this term.