Park opened the scoring inside 10 minutes and Berbatov added a double either side of the interval, before Valencia blasted home against his former club and Park won a penalty for Berbatov to confidently convert with 10 minutes remaining. City's unexpected stalemate at West Brom means now only goal difference separates the two title rivals.
A much-changed Reds side coped comfortably with widescale reshuffling, though their cause was aided by the harsh dismissal of Wigan striker Conor Sammon for a perceived elbow on Michael Carrick, who again deputised in defence.
Sir Alex Ferguson was forced to make several personnel changes to his side. Phil Jones and Chris Smalling missed out through illness, and were replaced by serial moonlighters Valencia and Carrick. In turn Darron Gibson stepped into midfield while Park took up a berth on the left wing and Nani shunted over to the opposite flank. The visitors, conversely, were unchanged from their previous outing. The Reds' perfect league record against the Latics had been aired repeatedly in the run-up to the match, but Roberto Martinez's side arrived at Old Trafford on the back of successive away wins at Sunderland and West Brom, as well as creditable home draws against Chelsea and Liverpool.
Buoyed by the champions' comparative unfamiliarity, Wigan's early approach demonstrated a willingness to commit numbers to counter-attacks, and one surging run from Victor Moses culminated in a shot which Carrick chested to safety. The bulk of the visitors' early play was, however, spent trying to congest central areas; a plan which United tore up inside eight minutes.