The Northern Ireland and former Preston striker set up two excellent chances for the hapless Brian Deane who spurned them both as Wigan maintained their unbeaten league record with a thoroughly deserved win.
Leeds, who have now won just once in their last eight matches, were caught cold less than a minute into the second half when a ball was played into Jason Roberts from the left and he released Alan Mahon.
The Irish midfielder, who interested Leeds when George Graham was in charge, fired a left-foot shot past Neil Sullivan from 18-yards.
Then, six minutes later, Roberts was again the provider with a pass down the right to Jimmy Bullard who cut inside and expertly found the gap between Sullivan and the far post.
Paul Jewell's side adopted a shoot on sight policy, but their accuracy deserted them in the first half, with Sullivan rarely called into action.
Clarke Carlisle was fortunate to stay on the field after two offences in rapid succession. The Leeds defender was shown the yellow card for joining an argument when team-mate Sean Gregan was brought crashing down by Lee McCulloch, who was booked for the 28th minute offence.
Then, with Roberts threatening to break clear, Carlisle shoved him to the ground and held his breath as referee Mike Dean chose to lecture him instead of ordering him off.
Simon Johnson, operating on Leeds' left flank for the second time in a week, after his recall from a loan spell at Sunderland, was full of running and gave David Wright a torrid time.
But Bullard and Mahon were at the hub of Wigan's best moves and won the tussle with Gregan and Simon Walton for midfield supremacy.