There was absolutely no hint of the thrashing to come in the first quarter of an hour, with the Latics more than holding their own against a lethargic United side. Steve Gohouri almost stretched successfully to connect his forehead with the ball after a thumping cross into the box from Charles N'Zogbia, before Edwin Van der Sar was forced to make a crucial save from Victor Moses.
The Wigan forward broke forward and found himself one on one with the Dutchman after a Paul Scholes error in midfield.
Just moments after that save from Van der Sar, United made the home team rue their early missed chances with a goal from the lively Javier Hernandez. Nani sprinted down the left for the away side and crossed in towards the feet of the Mexican, who flicked the ball into the back of the net past the helpless Ali Al-Habsi.
The ambition and pace that characterised Wigan's early play started to fall away after the opening goal, with the visitors looking far more comfortable on the ball. However, United's midfield seemed unwilling to hold on to the ball for any sustained period of time, with error after error allowing the hosts to gather momentum in the final third but with little end result.
The second half brought with it a rejuvenated Latics side, who reproduced the form they had shown in the opening quarter of an hour, pressing United in middle of the park and surging forward in numbers.
Maynor Figueroa forced Van der Sar, who had a majestic game in between the sticks, to tip the ball over the bar with a stinging shot from range and, just moments later, Hugo Rodallega directed a weak header into the arms of the waiting goalkeeper.
With the game starting to look stretched, it was United who grabbed the match by the scruff of its neck, Nani forcing Al-Habsi to punch his first-time shot clear before clearing off the line from Darren Fletcher. Although substitute Franco Di Santo had the ball in the back of the net for Wigan around the hour mark, he was rightly flagged offside and United continued their attempts to frustrate the hosts with a strange mixture of comfortable possession and erratic mistake all over the pitch.
It was left to a touch of magic from Hernandez to settle any nerves the travelling United fans may have been feeling, the Mexican weaving his way into the box and, before Wigan had any time to react, slamming the ball past the helpless Al-Habsi.
That goal saw Wigan's heads drop and opened up the floodgates for two late goals that made the scoreline a truly flattering one for the away side. Darron Gibson, on for Scholes, played a ball from his own half up towards Dimitar Berbatov, who sprinted towards goal before unselfishly playing in Wayne Rooney for a simple tap-in. Moments later, it just got worse for the Latics, with Fabio Da Silva scoring United's fourth of the game with what looked to be his first touch since coming on as a substitute, with a fine curling effort after some neat control.
United saw their lead at the top of the table extend to four points with the victory, but Wigan can rightly feel aggrieved to have been on the losing end of such a dominant scoreline.