The second defeat in three matches at the Stadium of Light was a bitter blow for the Black Cats who attracted a bumper crowd of more than 40,000 for the start of the busy hectic holiday period.
But there was no denying Leeds were worthy of their first win in six matches as they moved away from the danger zone.
A disappointing first half burst into life after the visitors had taken a shock lead on the half-hour, Aaron Lennon taking advantage of a misunderstanding between central defenders Gary Breen and Steve Caldwell.
Julio Arca was close to equalising moments later with a rasping drive that just cleared the bar but the Black Cats were on level terms in the 43rd minute. Matthew Spring brought down Dean Whitehead and Liam Lawrence easily beat Neil Sullivan from the penalty spot.
The lively Lawrence almost put Sunderland into the lead from a free-kick and Breen should have at least hit the target from a Lawrence corner when he was presented with a free header in front of goal.
However, the Black Cats were constantly under pressure from the burly presence of Brian Deane. David Healy squandered two good chances and Lennon fired straight at Thomas Myhre.
Chris Brown created a shooting chance for himself in the 52nd minute only for Sullivan to fling himself full length and turn the ball behind for another fruitless corner.
But Leeds restored their lead in the 61st minute. The determination of Spring set up the chance for Healy to cross to the far post and Deane thumped a header into the roof of the net.
Myhre saved well from Spring and Healy and though Arca rattled the post in the 76th minute, Leeds surged further ahead nine minutes later when substitute Julian Joachim was well-positioned to convert Jermaine Wright's cross.
Arca pulled a goal for the hosts in stoppage time from a 20-yard free-kick but it was too late to prevent a surprise defeat.