PETR CECH was sent off as Chelsea lost their 100 per cent start to the season.
Cech got an early bath for bringing down Hugo Rodallega as he charged through on goal.
The Wigan striker converted the spotkick as the Latics gained their first ever Premier League win against a Big Four team.
Titus Bramble had given the home side a shock lead with his first goal in 10 months.
Didier Drogba hit back for the Blues but Cech's sending-off turned the game Wigan's way, with Paul Scharner adding a third in injury time.
Chelsea almost made the breakthrough after two minutes as Michael Essien connected well with Ashley Cole's cutback. But Wigan keeper Chris Kirkland turned the ball behind.
Nicolas Anelka shot wide and Frank Lampard tested Kirkland with a free-kick as Chelsea looked for an early lead.
Lampard sent another effort wide of the post before Jason Scotland forced a good save from Cech.
Scotland's effort gave Wigan a shot of confidence and they stunned the league leaders soon after with the opening goal. Bramble got away from his marker and sent his header into the corner of the net following a cross from Charles N'Zogbia.
Chelsea hit back and Florent Malouda got on the end of a ball from Cole but his touch was poor and Kirkland was able to make the clearance.
Scharner clipped a shot over as Wigan kept up the pressure.
And the Blues needed a wonder save from Cech to prevent the Latics doubling their lead on 39 minutes.
Emmerson Boyce stole in to pounce on Scharner's flick but Cech made a point-blank stop to deny the defender.
And the visitors almost took the lead on 50 minutes, only for Scharner to block John Terry's effort after Ricardo Carvalho's flick-on.
The game took a dramatic turn a minute later when Cech was given a straight red card for tripping Rodallega as he raced into the area. Cech was incensed at the decision and so were his team-mates as a penalty was awarded.
Hilario stepped between the posts - with Malouda coming off - and his first job was to pick the ball out of the net with Rodallega converting his spot-kick.
Lampard put a header over as Chelsea looked for a leveller. But the visitors were reduced to nine men after Cole went off injured. And Scharner made sure of the points in injury time as he converted Maynor Figueroa's centre.
Wigan: Kirkland, Melchiot, Boyce, Bramble, Figueroa, Thomas, Rodallega, Diame, N'Zogbia, Scharner, Scotland (King 88). Subs not used: Pollitt, Amaya, Cho, Koumas, Gomez, De Ridder. Booked: Thomas. Goals: Bramble 16, Rodallega 53 pen, Scharner 90.
Chelsea: Cech, Bosingwa (Kalou 68), Carvalho, Terry, Ashley Cole, Essien, Mikel (Belletti 46), Malouda (Hilario 52), Lampard, Drogba, Anelka. Subs not used: Ivanovic, Zhirkov, Paulo Ferreira, Borini. Sent off: Cech (51). Booked: Carvalho, Essien. Goals: Drogba 47.
Att: 18,542
Ref: Phil Dowd (Staffordshire).
Cech got an early bath for bringing down Hugo Rodallega as he charged through on goal.
The Wigan striker converted the spotkick as the Latics gained their first ever Premier League win against a Big Four team.
Titus Bramble had given the home side a shock lead with his first goal in 10 months.
Didier Drogba hit back for the Blues but Cech's sending-off turned the game Wigan's way, with Paul Scharner adding a third in injury time.
Chelsea almost made the breakthrough after two minutes as Michael Essien connected well with Ashley Cole's cutback. But Wigan keeper Chris Kirkland turned the ball behind.
Nicolas Anelka shot wide and Frank Lampard tested Kirkland with a free-kick as Chelsea looked for an early lead.
Lampard sent another effort wide of the post before Jason Scotland forced a good save from Cech.
Scotland's effort gave Wigan a shot of confidence and they stunned the league leaders soon after with the opening goal. Bramble got away from his marker and sent his header into the corner of the net following a cross from Charles N'Zogbia.
Chelsea hit back and Florent Malouda got on the end of a ball from Cole but his touch was poor and Kirkland was able to make the clearance.
Scharner clipped a shot over as Wigan kept up the pressure.
And the Blues needed a wonder save from Cech to prevent the Latics doubling their lead on 39 minutes.
Emmerson Boyce stole in to pounce on Scharner's flick but Cech made a point-blank stop to deny the defender.
And the visitors almost took the lead on 50 minutes, only for Scharner to block John Terry's effort after Ricardo Carvalho's flick-on.
The game took a dramatic turn a minute later when Cech was given a straight red card for tripping Rodallega as he raced into the area. Cech was incensed at the decision and so were his team-mates as a penalty was awarded.
Hilario stepped between the posts - with Malouda coming off - and his first job was to pick the ball out of the net with Rodallega converting his spot-kick.
Lampard put a header over as Chelsea looked for a leveller. But the visitors were reduced to nine men after Cole went off injured. And Scharner made sure of the points in injury time as he converted Maynor Figueroa's centre.
Wigan: Kirkland, Melchiot, Boyce, Bramble, Figueroa, Thomas, Rodallega, Diame, N'Zogbia, Scharner, Scotland (King 88). Subs not used: Pollitt, Amaya, Cho, Koumas, Gomez, De Ridder. Booked: Thomas. Goals: Bramble 16, Rodallega 53 pen, Scharner 90.
Chelsea: Cech, Bosingwa (Kalou 68), Carvalho, Terry, Ashley Cole, Essien, Mikel (Belletti 46), Malouda (Hilario 52), Lampard, Drogba, Anelka. Subs not used: Ivanovic, Zhirkov, Paulo Ferreira, Borini. Sent off: Cech (51). Booked: Carvalho, Essien. Goals: Drogba 47.
Att: 18,542
Ref: Phil Dowd (Staffordshire).
