Wigan will continue their FA Cup defence with a semifinal against Arsenal at Wembley, after shocking Manchester City for the second straight season.
The Latics, who beat City in a dramatic final last season, were at their parsimonious best yet again as manager Uwe Rosler enjoyed an emotional win against his former club.
It felt like déjà vu from the Capital One Cup final last week, when Wigan took the lead in the first half, with the away team holding onto the scoreline at halftime as City yet again looked frustrated.
The goal came through the penalty spot, after Martin look-at-me-and-I-will-make-a-mistake Demichelis brought down Marc-Antoine Fortune inside the penalty area. Jordi Gomez duly stepped up and slotted into the back of the net, to send Wigan into the lead on 27 minutes.
Try as they might City could not break down the wonderfully marshalled Wigan rearguard, with skipper Emmerson Boyce, especially, having an inspired outing.
It looked like City would need another couple of top-draw goals, like the ones they managed to find against Sunderland at Wembley last weekend, but in a full body blow, it was Wigan who extended their lead just two minutes after the restart.
James McArthur was allowed to run into the penalty box by a static City defence, with the midfielder rolling a low cross into the six yard box, which James Perch, clearly wanting it more, got to ahead of the dilly-dallying Gale Clichy.
Manuel Pellegrini, left with little choice, made a triple substitution, bringing on David Silva, Edin Dzeko and James Milner, with inspirational midfielder Yaya Toure, on a yellow card and having a bad day, one of the players sacrificed.
As time wore on, City took complete control, with Wigan, desperate to protect their lead, dropping further and further back. Inevitably the lead was cut to 2-1 by City, with Samir Nasri firing a low drive from the edge of the box past Scott Carson, whose line of sight was impeded by an offside Joleon Lescott.
With another goal to find to at least take the FA Cup quarterfinal tie to a replay, City just kept attacking, with a couple of how-on-earth-did-that-not-go-in moments thrown in every few minutes.
However, the Championship side's resolve would not be broken, exemplified brilliantly by a near-unbelievable last-ditch challenge by Boyce to stop Dzeko from tapping in from close range, as the defending FA Cup champions stayed strong to take a stunning 2-1 victory.
The other semifinal at Wembley will be played between Hull City and Sheffield United, after the two teams got past Sunderland and Charlton Athletic respectively.
Three goals in nine second half minutes proved to be the difference for Hull as Curtis Davies, David Meyler, who celebrated the goal by head-butting the corner flag in an ode to the infamous Alan Pardew incident, and Matty Fryatt gave Hull a 3-0 win over Sunderland, still reeling from their painful League Cup final defeat.
Sheffield United set up a clash with Hull courtesy their own quickfire victory over Charlton, with Ryan Flynn, in the 65th minute, and John Brayford, two minutes later, giving the home fans at Bramall Lane a momentous 2-0 result.