Wigan secured Premiership survival and condemned Sheffield United to the drop with a dramatic win at Bramall Lane.
Wigan celebrate Paul Scharner's opener at Sheffield United
Paul Scharner's 14th minute strike put Wigan ahead, but Jon Stead's header put the Blades level after 38 minutes.
But former Blade David Unsworth kept Wigan up with a penalty in first-half injury-time after Phil Jagielka handled Kevin Kilbane's free-kick.
Sheffield United Danny Webber hit a post and Wigan had Lee McCulloch sent off in a frantic second period.
Wigan's win, combined with West Ham's victory at Manchester United, meant the Blades went back down into the Championship after one full season in the top flight on goal difference.
Paul Jewell's side knew only victory would assure Premiership safety, and they started with a verve that brought them a deserved lead after 14 minutes.
Kilbane's cross was met with a full-blooded left-foot strike from Scharner that flew beyond Paddy Kenny into the bottom corner.
Scharner then headed over the top, before Wigan suffered a blow after 31 minutes when captain Arjan de Zeeuw limped off with a calf injury.
It was the signal for the Blades' first real spell of pressure in the game and brought an equaliser seven minutes before the interval.
Stead showed incredible bravery to meet Jagielka's cross ahead of Wigan keeper Mike Pollitt and head home.
Both Stead and Pollitt required lengthy treatment before continuing, while Wigan lost Ryan Taylor with a leg injury sustained in the same incident.
Stead then missed a glorious chance to put Sheffield United ahead and push Wigan closer to the drop, only to shoot wide from just six yards.
Wigan took advantage of the reprieve to regain the lead in first-half injury time.
Jagielka inexplicably handled Kilbane's free-kick and Unsworth, who had replaced Taylor, scored from the spot with his customary expertise.
Emile Heskey had proved a real handful, and he almost extended Wigan's lead with an acrobatic over-head kick after 50 minutes that brought an equally spectacular save from Paddy Kenny.
The game was being played in a frantic atmosphere, on and off the pitch, and Danny Webber - a half-time substitute for Christian Nade - was agonisingly close to an equaliser for Sheffield United.
He raced clear and chipped over Pollitt, only for the ball to rebound off an upright and roll along the six-yard box to safety.
Wigan were under intense pressure with their Premiership survival at stake, and they were placed under even greater strain with 16 minutes left when McCulloch was sent off for a foul on Michael Tonge that brought him a second yellow card.
Sheffield United had dominated the second half, but had failed to make the breakthrough, with Stead's cross flying across the goalmouth with no-one able to apply the finishing touch.
Sheff Utd: Kenny, Jagielka, Morgan, Kilgallon, Geary, Gillespie, Montgomery (Davis 79), Tonge, Stephen Quinn (Kazim-Richards 56), Nade (Webber 46), Stead.
Subs Not Used: Bennett, Leigertwood.
Booked: Geary, Nade, Jagielka.
Goals: Stead 38.
Wigan: Pollitt, Taylor (Unsworth 42), De Zeeuw (Skoko 31), Boyce, Baines, Valencia, Scharner, Landzaat (Folan 77), Kilbane, Heskey, McCulloch.
Subs Not Used: Filan, Camara.
Sent Off: McCulloch (74).
Booked: Unsworth, McCulloch, Scharner, Valencia, Folan.
Goals: Scharner 14, Unsworth 45 pen.
Ref: M Dean (Wirral).