The Blues beat West Bromwich Albion comfortably 4-0 to cut the Reds' lead in the title race back to five points, with five games remaining.
Sergio Aguero settled City down with a goal after just six minutes and doubled their advantage early in the second half. Former United striker Carlos Tevez made it 3-0 with his first goal of the season three minutes before David Silva chipped in the fourth.
The Blues' emphatic win at the Etihad and United's 0-1 defeat at the DW Stadium means Roberto Mancini's men now have a better goal difference, by +53 to +50.
Wigan's victory has boosted their bid to stay in the top flight, lifting them out of the relegation zone into 17th place. Survival rivals Queens Park Rangers remain above them on goal difference after beating Swansea City 3-0 at home, a