Sunderland's automatic promotion hopes suffered a massive blow after Wigan came from behind to win 2-1 at the DW Stadium.
Latics picked up their second win in four days to move out of the relegation zone with five matches to go.
But after back-to-back setbacks, the Black Cats look like they may have to make do with the play-offs.
It looked good for the visitors when Aiden McGeady's cross was turned in by Charlie Wyke in the 32nd minute, with the Wigan defence to a man waiting for an offside flag that never came.
But Wigan were perhaps unfortunate to find themselves behind, and levelled through Will Keane 10 minutes later.
Callum Lang put the home side ahead in the 58th minute with a cool finish from close range.
And Wigan could have won by even more, with Keane missing a couple of glorious chances to make the game safe before the end.