Franco di Santo's late strike moved Wigan off the bottom of the Premier League and heaped pressure on Sunderland manager Steve Bruce.
Wes Brown messed up a Keiren Westwood clearance in stoppage time and James McArthur nipped in before setting up Di Santo - who slotted into an empty goal.
Sunderland have only won once in 10 but they went ahead as Sebastian Larsson pounced on Ali Al Habsi's error.
Jordi Gomez equalised with a penalty before Di Santo nicked the win late on.
It was Wigan's first away win of the season - and only their second overall - but they are now within two points of Sunderland and escaping the relegation zone.
Wigan went into the game low on confidence with just one win from their previous 12 encounters and their spirits took a further hammering when they went behind after eight minutes.
Sunderland have hardly been high in belief either with just one league victory at the Stadium of Light this season before Wigan's visit but the return of Larsson from suspension inspired them.
Sunderland's top-scorer pounced when Al Habsi fumbled Bendtner's rather tame shot into the path of Kieran Richardson.
The Latics keeper did manage to close Richardson down but the ball spun to Larsson and he smashed home his fourth of the campaign in Sunderland colours.
Al Habsi was called upon to save from Richardson and the visiting keeper went some way to making up for his earlier error when he denied Brown's header after the defender rose to head Larsson's resulting corner.
Did you know?
- Sunderland have only won one of their last nine home games since beating Wigan 4-2, and managed a mere 10 points out of a possible 45.
Wigan manager Roberto Martinez was probably preparing a stern talking to for his charges until Victor Moses was tackled in the penalty area by Larsson and, despite the Swedish midfielder's protests, referee Kevin Friend pointed to the spot.
Gomez calmly stepped up to send Westwood in the wrong direction and grab his second goal of the season.
After a frantic opening half for the hosts, their pace dramatically slowed down after the break but Richardson did have a glorious chance with 10 minutes remaining.
Jack Colback burst down the left before crossing for the former Manchester United midfielder but he headed wide from close range.
The late drama came deep into stoppage time, however, as Brown played a ball back to Westwood.
The Sunderland keeper lobbed the ball back to his defender but it came off his knee and McArthur was alert to dispossess Brown.
He played the ball across the area to fellow substitute Di Santo who, with Westwood out of position, had the simplest of finishes as he slid the ball into an empty net.
The win - Wigan's first since they overcame QPR in August - is timely ahead of matches against Arsenal, Chelsea, Liverpool and Manchester United in four of their next five outings.
Live Text Commentary
Full Time The referee blows for the end of the match.90:00 +3:41
Dong-Won Ji takes a shot from just inside the penalty box which clears the bar.90:00 +2:04
Assist by James McArthur.90:00 +2:04 Goal scored
Goal! - Franco Di Santo - Sunderland 1 - 2 Wigan Franco Di Santo finds the back of the net with a goal from inside the six-yard box low into the middle of the goal. Sunderland 1-2 Wigan.90:00 +1:04
Unfair challenge on Jack Colback by Mohamed Diame results in a free kick. Keiren Westwood restarts play with the free kick.88:29
Franco Di Santo fouled by David Vaughan, the ref awards a free kick. Steve Gohouri restarts play with the free kick.87:43
Foul by Maynor Figueroa on David Vaughan, free kick awarded. Sebastian Larsson crosses the ball from the free kick right-footed from right channel, clearance by Gary Caldwell.86:41
The referee blows for offside against Dong-Won Ji. Gary Caldwell restarts play with the free kick.85:56
Kieran Richardson takes a shot. Save by Ali Al Habsi.83:20
Free kick taken by Keiren Westwood.83:20 Substitution
Substitution Dong-Won Ji on for John O'Shea.83:20 Substitution
Substitution Franco Di Santo replaces Conor Sammon.83:20 Booking
Booking Mohamed Diame booked for unsporting behaviour.83:08
Mohamed Diame challenges Sebastian Larsson unfairly and gives away a free kick.78:45
Free kick awarded for a foul by Victor Moses on John O'Shea. Free kick taken by John O'Shea.77:27
Close range header by Kieran Richardson misses to the right of the target.74:47
Victor Moses concedes a free kick for a foul on Sebastian Larsson. Direct free kick taken by John O'Shea.73:01
Free kick crossed right-footed by Jordi Gomez from right channel.73:01 Substitution
Substitution James McArthur on for Ronnie Stam.73:01 Booking
Booking Jack Colback booked for unsporting behaviour.
Free kick awarded for a foul by Jack Colback on Ronnie Stam.71:26
Effort from the edge of the box by Kieran Richardson goes wide of the right-hand upright.70:09
Mohamed Diame produces a shot on goal direct from the free kick.70:09 Booking
Booking Michael Turner receives a caution for unsporting behaviour.69:58
Michael Turner concedes a free kick for a foul on Victor Moses.68:15
Inswinging corner taken right-footed by Sebastian Larsson from the left by-line to the near post, clearance by David Jones.67:17
Free kick awarded for a foul by Mohamed Diame on Stephane Sessegnon. Free kick crossed right-footed by Sebastian Larsson from left channel, clearance by Gary Caldwell.65:35
Free kick taken by Keiren Westwood.65:35 Substitution
Substitution (Sunderland) makes a substitution, with Craig Gardner coming on for Lee Cattermole.65:35 Substitution
Substitution David Vaughan is brought on as a substitute for Phillip Bardsley.65:35
Conor Sammon is caught offside.64:13
Jordi Gomez challenges Sebastian Larsson unfairly and gives away a free kick. Sebastian Larsson crosses the ball from the free kick right-footed from left wing.61:11
Short corner worked by David Jones, clearance made by Michael Turner.60:09
David Jones takes the direct free kick.60:09 Booking
Booking John O'Shea shown a yellow card.59:57
John O'Shea gives away a free kick for an unfair challenge on Victor Moses.55:36
Nicklas Bendtner challenges Maynor Figueroa unfairly and gives away a free kick. Free kick taken by Maynor Figueroa.55:06
Ronnie Stam has an effort at goal from outside the penalty box which goes wide left of the goal.52:52
Effort from outside the penalty box by Nicklas Bendtner goes wide right of the target.50:48
Mohamed Diame takes a shot. Save by Keiren Westwood.48:49
Jack Colback takes a shot. Ronnie Stam gets a block in.47:28
Ali Al Habsi crosses the ball.46:55
Nicklas Bendtner has an effort at goal from outside the box which goes wide right of the goal.45:01
The referee starts the second half.45:00 +1:48 Half time
Half Time The match has reached half-time.44:40
Stephane Sessegnon gives away a free kick for an unfair challenge on James McCarthy. Direct free kick taken by Gary Caldwell.43:27
Victor Moses provided the assist for the goal.43:27 Goal scored
Goal! - Jordi Gomez - Sunderland 1 - 1 Wigan Jordi Gomez scores a placed penalty. Sunderland 1-1 Wigan.42:15
Penalty awarded for an unfair challenge on Victor Moses by Sebastian Larsson.40:29
Kieran Richardson is caught offside. Free kick taken by Maynor Figueroa.38:29
Phillip Bardsley produces a right-footed shot from inside the area that clears the bar.33:30
Free kick awarded for an unfair challenge on Jordi Gomez by Stephane Sessegnon. Ronnie Stam takes the direct free kick.32:40
Sebastian Larsson takes a outswinging corner to the near post.31:21
Foul by James McCarthy on Stephane Sessegnon, free kick awarded. Sebastian Larsson sends in a cross, John O'Shea takes a shot. Save made by Ali Al Habsi.25:42
Lee Cattermole concedes a free kick for a foul on Jordi Gomez. Free kick taken by Gary Caldwell.25:31
Nicklas Bendtner takes a shot. Blocked by Gary Caldwell.23:20
Free kick awarded for an unfair challenge on Maynor Figueroa by Jack Colback. Gary Caldwell restarts play with the free kick.22:47
Phillip Bardsley takes a shot. Save made by Ali Al Habsi.21:13
Ronnie Stam gives away a free kick for an unfair challenge on Stephane Sessegnon. Direct effort from the free kick comes in from Sebastian Larsson, Ali Al Habsi makes a save.19:37
Effort on goal by David Jones from outside the area goes harmlessly over the bar.14:47
Outswinging corner taken by Sebastian Larsson, Wes Brown takes a shot. Save by Ali Al Habsi.14:25
Kieran Richardson takes a shot. Save by Ali Al Habsi.13:12
Free kick awarded for a foul by Mohamed Diame on Jack Colback. Free kick taken by Keiren Westwood.11:44
Unfair challenge on Jack Colback by James McCarthy results in a free kick. Jack Colback restarts play with the free kick.9:50
Victor Moses gives away a free kick for an unfair challenge on John O'Shea. Free kick taken by John O'Shea.7:36
The assist for the goal came from Kieran Richardson.7:36 Goal scored
Goal! - Sebastian Larsson - Sunderland 1 - 0 Wigan A goal is scored by Sebastian Larsson from inside the six-yard box to the top left corner of the goal. Sunderland 1-0 Wigan.7:34
Kieran Richardson takes a shot. Save by Ali Al Habsi.7:07
Nicklas Bendtner takes a shot. Save made by Ali Al Habsi.5:48
Stephane Sessegnon gives away a free kick for an unfair challenge on Jordi Gomez. Direct free kick taken by Gary Caldwell.5:26
Jordi Gomez takes a shot. Keiren Westwood makes a save.3:50
Free kick awarded for an unfair challenge on Phillip Bardsley by Jordi Gomez. Free kick taken by Phillip Bardsley.2:31
Inswinging corner taken by David Jones from the right by-line, Keiren Westwood makes a save.2:15
Victor Moses takes a shot. Wes Brown makes a clearance.1:37
Free kick awarded for an unfair challenge on Jordi Gomez by Lee Cattermole. Direct free kick taken by Gary Caldwell.0:00
The game gets underway.
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