A late Max Power strike secured the three points for Latics in a pulsating encounter at the ABAX Stadium as they overcame the Posh 3-2 to move up to seventh in the League One table.
Wigan weathered early pressure from Peterborough before going into a two goal lead through Yanic Wildschut and Will Grigg.
But the Posh fought back to draw level through Erhun Oztumer and substitute Souleymane Coulibaly.
Just when it looked like Peterborough might go on to win it, Wigan had the final say when Power raced onto Craig Davies’s pass and finished in great style.
Gary Caldwell unsurprisingly named the same team which defeated Colchester for the fixture at the ABAX Stadium.
It was Peterborough who made the early running with a series of goalscoring opportunities.
First Michael Bostwick headed Erhun Oztumer’s corner wide after only four minutes. Jon Taylor fired wide of Jussi Jaaskelainen’s opposite post from Conor Washington’s cross, before Craig Morgan had to block an effort from Taylor when he may have gone on to score.
But against the run of play Latics went ahead with their first serious attack and it was that man Yanic Wildschut who did the damage.
The big Dutchman broke quickly from midfield and through his sheer power bulldozed his way through the Peterborough defence before tucking the ball under Ben Alnwick from just inside the area.
Wigan stormed forward boosted by Wildschut’s goal. The Middlesbrough loanee was creating all kinds of problems and the Posh simply couldn’t cope with his pace and power.
He created another opportunity soon afterwards, but the ball was cleared by Ricardo Santos, before Grigg could get the final touch. Power then blasted a shot across the Posh goalmouth.
But it was not long before Latics were 2-0 up. Wildschut unsurprisingly creating the goal. He picked up the ball on the left flank and drove at his full back before cutting the ball back to Reece James whose shot looked to have beaten Alnwick, but probably got a touch off Grigg before going into the net.
It was end to end stuff now as Peterborough tried to respond. Taylor had an effort that went just wide, before Gabriel Zakuani headed over.
Latics pressed again Wildschut and the winger’s low shot was well saved by Alnwick.
Lee Angol and Chris Forrester had shots from distance for Peterborough but Jussi Jaaskelainen was relatively untroubled.
Wigan might have increased their lead when Michael Jacobs fired a low effort across the face of goal which Alnwick had to palm away. Chris McCann then shot straight at Alnwick when an effort either side of the keeper would have probably beaten him. Will Grigg then had his effort pushed away by the keeper.
What an incredible half with numerous chances and with both teams looking good going forward and vulnerable defensively.
The second half continued in similar fashion to the first.
Forrester almost immediately received a yellow card for bringing down Wildschut who was tearing towards the Peterborough goal.
Soon afterwards Jacobs appeared to be pushed over in the penalty area but nothing was given.
Wildschut freed Jacobs and his shot from the edge of the area just missed the upright.
Wildschut earned a free-kick just outside the area and Jacobs low curled shot evaded the Peterborough defensive wall but was well saved by Alnwick. Reece James then powered the ball across the area, but no Wigan player could make the final contact.
Surely Latics would add to their lead soon?
But it was Peterborough who scored next.
Taylor struck with a fierce shot which Jaaskelainen was unable to hold and Oztumer blasted the ball home from close range.
Peterborough now felt they had a foothold in the game and could draw level. Washington’s shot from the left side beat Jaaskelainen but also the far post. Jermaine Anderson headed wide from Callum Elder’s cross.
Craig Davies then replaced a very tired looking Wildschut as the game moved towards an amazing finale.
First Peterborough drew level. Oztumer’s low cross was turned in by substitute Souleymane Coulibaly on 81 minutes.
Would Latics now succumb to Peterborough pressure? The answer was an emphatic ‘No’, as they went straight up the other end and scored a superb goal.
Davies exchanged passes with Power and the former Tranmere midfielder finished with great aplomb much to the delight of the travelling Wigan fans.
Latics had to endure an agonising six minutes of additional time, but they held on to record an important victory and move the team to within seven points of the top spot.