The defender had levelled with 12 minutes to go when he glanced in Joe Rothwell’s wicked free-kick and then won it in added time with another header from another Rothwell cross.
Sunderland had taken the lead against the run of play when French striker Wilson Isidor got on to defender Dan Ballard’s clipped pass into the inside right channel and did excellently to spin Leeds skipper Ethan Ampadu before lashing a low shot in off the far post.
The Whites had not been behind at the break in a league match at Elland Road since their only home defeat this season by Burnley in September.
But this time they turned it around in the most unlikely of endings and are now seven points clear of the third-placed Clarets with 13 games to play.
The win stretches their unbeaten run to 15 league games and they remain undefeated in front of their own fans since 15 September.
Sunderland’s players dropped to the ground as Leeds’ bench emptied to celebrate the late, late winner and their slim automatic promotion chances look distant now.