Catalans Dragons: (10) 16
Tries: Murphy, Chan
Goals: Gorrell (4)
Wigan: (6) 18
Tries: Ashton, Bailey, O'Loughlin
Goals: Richards (3)
Sean O'Loughlin's last-gasp try sealed a dramatic late victory for Wigan over the Catalans Dragons in Perpignan.
The Wigan captain went over in the 78th minute and Pat Richards added the extras for a victory which seemed beyond them for much of the game.
The Dragons had led thanks to tries from Alex Chan and Justin Murphy, as well as Aaron Gorrell's kicking.
But Phil Bailey's effort gave Wigan hope and, with Gareth Hock in the sin bin, they dug deep to get the points.
The result ruined the party for Catalans, who returned to their redeveloped Gilbert Brutus Stadium for a game that only got the go-ahead after a pitch inspection.
Earlier, there had been serious doubts whether the match could take place as heavy rain poured down in the south of France.
The Dragons adapted better to the conditions to capitalise on a string of Wigan errors and take a 10-6 interval lead through Chan's try and a Gorrell conversion and two penalties, with Chris Ashton responding for the visitors.
Both sides had tries ruled out shortly after the restart before the Dragons edged further ahead through Murphy, but it was Wigan who ensured the late drama.
Dragons coach Mick Potter "I thought it was a good performance from us. Wigan kept tearing at us, they never gave up.
"I thought it was terrific that more than 7,000 fans turned out given the bad conditions for a game that went down to the wire."
Wigan coach Brian Noble "We played a little dumb, we gave away too many penalties and gave away too much of the ball.
"But there are lessons to be learned from that and I'm sure we will get better.
"We scored three very good tries and showed lots of skill."
Catalans Dragons: Greenshields, Murphy, Duport, Mogg, Pelo, McGuire, Wilson, Fellous, Gorrell, Guisset, Chan, Croker, Mounis. Replacements: Ferriol, Teixido, Gossard, Casty.
Wigan: Ashton, Calderwood, Bailey, Vaealiki, Richards, Barrett, Leuluai, Fielden, Millard, Paleaaesina, Hock, Fletcher, O'Loughlin. Replacements: Withers, Hansen, Higham, O'Carroll.
Referee: I Smith (Oldham)