The Lancashire side had snatched the lead after a blunder in the Wednesday defence, before Preston keeper Andy Lonergan gifted the Sheffield side a goal minutes after the restart, with Jeffers having the final word.
Colchester reignited their survival hopes with a Kevin Lisbie-inspired win at Charlton Athletic.
Lisbie, who struggled to score goals in his years as an Addicks player shattered his former team with a brace in the first 29 minutes.
He opened the scoring from the penalty spot on 15 minutes after he himself had been brought down by Patrick McCarthy, and a mistake by McCarthy allowed the Colchester striker to net his second with an overhead kick on 29 minutes to give the Us a crucial two-goal lead.
Luke Varney got his side back into the match with a goal right on half-time, converting Lloyd Sam's cross from close range, but the London side failed to create many chances to level.
New strikers Steve Howard and Barry Hayles were unable to prevent Leicester City slumping to defeat at rejuvenated QPR.
The Foxes' former Rangers manager Ian Holloway endured a miserable return to Loftus Road and Hayles - recently signed from Plymouth - barely troubled the home defence.
Goals from Damion Stewart, Adam Bolder and Dexter Blackstock put QPR in command, before Iain Hume pulled one back for the Foxes
Two goals in the final 15 minutes continued Ipswich's amazing home form as they downed leaders West Brom.
Fortress Portman Road proved unbreachable once again as Town extended their unbeaten home streak to 17 games - 15 wins and two draws - thanks to headers from defenders David Wright and Jason De Vos.
Watford took advantage of the Baggies' slip-up at to draw level on points at the top of the table after slamming three past Southampton.
Damien Francis, Tommy Smith and Darius Henderson netted as they left the south coast with victory.
Bristol City held off a spirited fightback by Coventry to keep their place in the big Premier League chase.
After building a two-goal lead with an early strike from Darren Byfield and a second-half header by Marvin Elliott, they thought the game was theirs.
But Dele Adebola fired up the Sky Blues with a goal 18 minutes from the end and they only missed out on a point when Leon Best rolled his shot against a post after beating keeper Adriano Basso.
Blackpool ran riot against Burnley at Bloomfield Road, with Kaspars Gorkss, Ben Burgess and Claus Jorgensen netting in a 3-0 rout of the Clarets.
Stoke City lost ground in the race for promotion, but were fortunate to take a point against impressive Hull. Carl Cort put the Potters ahead at the Brittannia Stadium, with Caleb Folan levelling for the Tigers.
Crystal Palace extended their recent unbeaten run to 13 matches after a 1-1 draw with Norwich at Selhurst Park, Clinton Morrison levelled Darel Russell's early opener.
Wolves and Sheffield United did little to ease the pressure on their respective managers, Mick McCarthy and Bryan Robson, as they fought out a frustrating stalemate at Molineux.