After United drew a blank in the midweek 0-0 Champions League draw with Olympique Marseille, manager Sir Alex Ferguson restored Mexican international Hernandez to the line-up alongside Wayne Rooney, with Dimitar Berbatov relegated to the bench.
On a day when the five sides below United were not playing, including second-placed Arsenal, who faced Birmingham City in the League Cup Final on Sunday, Hernandez justified his selection with his eighth and nine league goals of an impressive first season in English football.
Hernandez has started just eight of United's 27 league games, with 10 more appearances from the bench.
"We played really well in the second half and had some fantastic opportunities. We opened them up time and time again and could have scored more. But I'm happy with 4-0," Ferguson told MUTV.
"We have a big week ahead and it's a good start," added the Scot, whose side play away at fifth-placed Chelsea on Tuesday and then travel to Anfield to play bitter rivals Liverpool next Sunday.
SLOTTED IN
Hernandez touched in Nani's cross at the near post to give United the lead on 17 minutes and he slotted in his second 16 minutes from time after linking up with Rooney.
The England striker then tapped in a third on 84 from substitute Berbatov's pass and defender Fabio da Silva got the fourth.
Despite the four-goal romp, Ferguson praised the contribution of Dutch goalkeeper Edwin van der Sar who made a number of key saves while the game was goalless.
"His composure is just outstanding as is his organisation of the defenders," Ferguson said. "Wigan were terrific in the first 20 minutes and van der Sar had to make some great saves."
Wolverhampton Wanderers moved off the foot of the table and out of the bottom three by thrashing 10-man Blackpool 4-0 at Molineux.
Sylvan Ebanks-Blake scored twice for Wolves, who made their extra man count after Blackpool's leading scorer DJ Campbell was sent off just before halftime for raising his hands at Richard Stearman.
"I spoke in the week about it being our biggest game and we've dealt with it very professionally," Wolves manager Mick McCarthy told BBC Sport.
"We had a fabulous goal to start with (by Matt Jarvis) and then they had a player sent off...maybe it was our lucky day."
In other games, Jermaine Beckford scored twice to give Everton a much-needed 2-0 win at home to Sunderland and Ashley Young also netted two as Aston Villa won 4-1 at home to Blackburn Rovers, who had defender Ryan Nelsen sent off. Newcastle United and Bolton drew 1-1.
