Paul Scharner opened the scoring 14 minutes into the game but Jonathan Stead levelled with a heroic header seven minutes from half-time. But former Sheffield United defender David Unsworth dispatched a penalty after Phil Jagielka hand balled.
Sheffield United striker Danny Webber hit the post in the second half whilst Athletic saw Lee McCulloch sent off.
There was still hope for United, if Manchester United beat West Ham United at Old Trafford they the Blades would stay up. However a Carlos Tevez goal on the stroke of half-time saw the Hammers snatch an away win, plummeting the Blades into the Championship.
Athletic opened the scoring on 14th minute when Paul Scharner latched onto Kevin Kilbane's cross, drilling the ball hard and low beyond the stretching Paddy Kenny.
The Austrian then headed over the top before Arjan de Zeeuw, on 31 minute was forced to retire with a calf injury.
Seven minutes before half-time the Blades levelled the score after finally breaking through the Wigan defence, Phil Jagielka crossed into the box from the right where Jonathan Stead beat keeper Mike Pollit to the ball to head home.
However in the aftermath both Stead and Pollit along with challenging defender Ryan Taylor were all injured, Taylor was stretched off with a injured leg whilst Stead and Pollit were okay to continue.
The former Sunderland striker then missed a glorious opportunity to but United ahead and Wigan closer into the mire, but somehow shot wide from six yards.
Jagielka was then judged to have hand balled in the penalty area after Kilbane's cross and Unsworth duly dispatched, driving the ball hard and low to his right hand side.
In the second half the excitable Emile Heskey almost doubled the visitors lead, his over head kick on 50th minute mark was spectacularly saved by Paddy Kenny.
From then on it was all United, Danny Webber (who had replaced Christian Nade at half-time) should have levelled for the Blades, how he didn't score is a mystery. He chased through and when one-on-one with Pollit chipped over the keeper, somehow it rebounded off the post and away from danger - another game, another day would have been a goal.
Wigan were under immense pressure and were forced to fight with backs to the wall when Lee McCullock was handed his second yellow of the match after a foul on Michael Tonge.
Despite their chances Sheffield United just couldn't put them away, and with the Hammers winning at Old Trafford it spelt curtains for the Blades.