Sheffield United's hopes of staying in the Championship hang by a thread after a defeat at fellow strugglers Preston.
Keith Treacy opened the scoring after the break with a 30-yard effort and doubled Preston's lead with a strike into the top corner from 18 yards.
Jordan Slew hit back for the Blades with a shot from the edge of the box.
Darius Henderson hit the post for the Blades before Nathan Ellington's strike sealed Preston's win to leave the away team eight points from safety.
North End are four points adrift of Crystal Palace, who are 21st in the table, with four games of the season remaining.
Phil Brown's Preston have won their last three home fixtures and are in reasonable overall form as they look forward to the remainder of the campaign.
The Blades have lost their last four games and were second best for long periods at Deepdale.
North End had a good chance in the opening minutes but striker Chris Brown could not keep his header on target from Treacy's cross.
Treacy, who had a spell on loan at Bramall Lane last season, then narrowly missed from 18 yards, while Iain Hume also went close.
The Blades bounced back and both Harry Maguire and Stephen Quinn went close for the visiting side, while Ian Turner denied Slew with a low shot.
Preston responded and although Brown should have done better from 12 yards, Treacy did eventually put the home side ahead, setting North End on their way to a crucial three points.