JAMES McClean made the first and scored the second as Malky Mackay received the perfect belated Christmas present - his first win since taking charge last month.
Latics were on the back foot for the majority of the game, but for once made the most of what chances came their way to register a crucial win at the foot of the Championship table.
The opening goal came on 10 minutes when McClean’s dangerous cross from the left was bundled past his own goalkeeper in almost comical fashion by Liam Cooper.
Mackay’s men then had to dig in and withstand a real barrage from a Leeds side who had started the day seven points ahead of their opponents but looking over their shoulders after a wretched recent run.
Scott Carson, playing behind a new-look five-man defence, was equal to everything that came his way to record a much-needed clean sheet.
The ex-England stopper did well to deny Mirco Antenucci and Billy Sharp, who then hit the bar with a looping header as the home side pressed further.
Marc-Antoine Fortune nearly made it 2-0 just before half-time only to see his shot cannon back off the legs of goalkeeper Marco Silvestri.
But it was Wigan’s defence who really earned their money after the break as Leeds, with Steve Morison on as a half-time substitute, threw everything at an equaliser.
Giuseppe Bellusci tested Carson with a fine effort, and the defender had to be on his guard at the other end as Don Cowie tried to get on the end of a McClean cross.
Despite the second half being played almost exclusively in Wigan territory, the visitors were looking increasingly dangerous on the break and secured the points with 10 minutes to go.
After a lovely move involving several players, Cowie picked his moment superbly to play in McClean in the left channel.
The Irishman controlled well before smashing the ball past Silvestri to the delight of the away end - 500 of whom had taken advantage of half-price tickets courtesy of their generous team.
Latics move up a place to 22nd in the table, but will benefit from a massive shot in the arm confidence-wise ahead of Tuesday’s visit of Sheffield Wednesday.
FOR A FULL MATCH REPORT, PICTURES AND REACTION, SEE SATURDAY’S WIGAN EVENING POST.