Former Wednesday striker Richard Cresswell snatched a 79th minute goal to leave the Hillsborough side still anchored at the foot of the First Division.
The forward, who spent 18 months at Hillsborough, struck after Wednesday had squandered a handful of first-half chances.
Wednesday were gifted a chance with just two minutes gone after Shefki Kuqi surged towards the area with defender Michael Jackson in pursuit.
Jonathan Gould came out to clear kicking the ball straight to the waiting Lee Bradbury, but with an open goal in front of him the on-loan striker slammed a tame shot straight at the keeper.
Midfielder Alan Quinn lashed a right-foot strike clear of the target from the edge of the area as Wednesday looked for an early breakthrough, Kuqi almost found it, but mistimed his header as he dragged the ball wide from a Quinn free-kick.
Wednesday were caught on the break in the 12th minute, George Koumantarakis producing a stunning left-foot shot on the turn from 15 yards, the ball taking a deflection as it spun wide of the goal.
Eddie Lewis went even closer minutes later twisting past his marker, his close-range shot snapped up by Paul Evans guarding the near post.
Graham Alexander pulled a free-kick wide before Koumantarakis almost found a way through six minutes before the interval as he steamed in to meet Paul McKenna's low cross into the goalmouth.
Evans was quickly down to make a brave save at the feet of the Greek-born South African international.
Former Preston defender Brian Barry-Murphy went close minutes after the restart after Quinn's shot had been blocked. The Wednesday full-back ran on to the loose ball, his stinging left foot shot from 18 yards hitting the sidenetting.
The lively McKenna almost the deadlock in the 58th minute running on to a Lee Cartwright pass, his low long-range strike crashing against the foot of the post.
Evans foiled Preston minutes later after Cresswell pumped in a low cross, Koumantarakis stepped over the ball and Lewis snap-shot was smothered by the Wednesday keeper.
Cresswell hit the winner in the 79th minute after Evans had pushed Koumantarakis' shot on to the bar, with the Preston striker reacted instantly slamming the ball past the stranded Wednesday keeper.