Lee McCulloch gave Wigan the lead on 26 minutes, stabbing in from close range but Preston were unlucky to see Chris Lucketti's effort ruled out.
Wigan streaked clear after the break though as Alan Mahon finished well to make it 2-0 on 50 minutes.
Nathan Ellington scored a brace, following up a simple header with a deflected fourth, while Jason Roberts' late penalty completed the rout.
Wigan boss Paul Jewell:
"The result looks one-sided but in the first half I was glad to get them in at half-time. They were better than us at that stage and we battled it out.
"I told them to have more belief. We are one of the best teams in the league and I told them to show it.
"We weren't playing with confidence but once the second goal went in we showed our true colours and showed we can play.
"Goals change games and after the second, you could see the confidence flowing through the lads again. We've had a blip but hopefully that's out of the way now."
Preston boss Billy Davies:
"We went from putting in our best performance of the season last week against Derby to the worst here.
"Wigan thoroughly deserved their victory and we've got to accept it's been a bad day at the office.
"We did okay in the first half without really passing the ball well, we weren't as fluent as last week, but all in all we were very sloppy.
"We have to pick up the pieces and get working again - we have an awful lot of work to do and a long way to go, so we have to keep encouraging people to work hard."
Wigan: Filan, Eaden, Breckin, Jackson, Baines, Teale,
Bullard (Wright 76), Mahon (Flynn 82), McCulloch, Roberts,
Ellington (Graham 84). Subs not used: Walsh, McMillan.
Booked: Bullard.
Goals: McCulloch 27, Mahon 52, Ellington 57, 72, Roberts 79 pen.
Preston: Gould, Mawene (Lewis 60), Lucketti, Davis, Alexander,
Sedgwick, O'Neil, Etuhu, Broomes, Cresswell, Agyemang. Subs not used: Ward, Davidson, Daley, Lynch.
Booked: Broomes, O'Neil.
Att: 10,565
Ref: M Atkinson (W Yorkshire).