Juan Mata's last-gasp winner moved Chelsea to within two points of the top four after Branislav Ivanovic's controversial opener set them on course for a 2-1 win over Wigan on Saturday.
Mata found himself in the right place at the right time to turn home from close range after Fernando Torres had fired a volley against the post in the third minute of stoppage-time at Stamford Bridge.
But it was Chelsea's first goal that sparked a furious reaction from Wigan, who were convinced the Serb was well offside when his turned home a Raul Meireles cross.
Referee Mike Jones ignored the protests of the visitors and awarded the goal after consulting with his assistant, although replays supported Wigan's claims that they had been hard done by.
Wigan's misery didn't end there and they left empty-handed after believing they had secured a deserved point after Mohamed Diame's 82nd minute effort had cancelled out Ivanovic's 62nd minute strike.
Chelsea are now up to fifth, above Newcastle on goal difference, and within two points of fourth placed Arsenal, who host Manchester City on Sunday.
Newcastle United, who won 2-0 at Swansea City on Friday to continue their strong form, are level on points with Chelsea.
Chris Herd's goal after a mistake by stand-in goalkeeper Doni looked to have given Aston Villa victory at Liverpool but Luis Suarez's 82nd-minute header made it 1-1 and avoided eighth-placed Liverpool's seventh loss in eight league games.
Third-bottom Blackburn Rovers lost 3-0 at West Bromwich Albion and Bolton Wanderers are just a point clear of danger following a 3-0 home defeat by Fulham. Basement side Wolverhampton Wanderers travel to Stoke City in the late game.
Rome: AC Milan allowed a 90th-minute goal by Fiorentina striker Amauri to lose 2-1 at home on Saturday and extend its struggles after being eliminated from Europe by Barcelona four days ago.
The loss kept Milan only two points ahead of Juventus at the top of Serie A, and gave the Turin side a chance to take the lead when it visited Palermo later. Milan took the lead with a penalty from Zlatan Ibrahimovic in the 31st at the San Siro but Stevan Jovetic equalized in the 47th after taking advantage of a Milan defensive lapse.
Amauri then finished off an exchange with Jovetic for his first goal since transferring from Juventus in January.
It was the fourth consecutive match in all competitions without a win for Milan, which drew 1-1 with Catania last weekend between a draw and a loss in its two-leg Champions League tie with Barcelona.
"It wasn't a great week, but we've got to bounce back, because everything is still up in the air,'' Milan manager Massimiliano Allegri said. "We've got to accept the result."