Wigan boss Steve Bruce fielded a much-changed side but knocked former Manchester United team-mate Roy Keane's Sunderland out of the FA Cup.
Scharner grabbed the opening goal at the Stadium of Light
Paul Scharner was left unmarked to give the visitors a half-time lead when he headed in Josip Skoko's free-kick.
Jonny Evans's poor back-pass let in Julius Agahowa and as he ran through on goal, Paul McShane tried to clear but put the ball past his own goalkeeper.
Dave Cotterill later made it 3-0 with a beautifully struck effort.
Keane had pledged to field his strongest possible side, but still made five changes after his squad were hit by injuries and suspensions.
But Bruce rang the changes even more, only naming four of the players from the midweek 1-1 draw with Liverpool in his starting line-up - and two of those, Ryan Taylor and Emile Heskey, went off injured during the game.
Scharner's opener was one of very few first-half chances, as Sunderland's inexperienced front pairing of Daryl Murphy and Martyn Waghorn were left isolated up front.
But soon after McShane and Nyron Nosworthy had collided with each other when they tried to clear the same ball, the Black Cats' defence was called into question once more as Evans played his team-mates into trouble.
Substitute Andy Cole set up Murphy who went close to pulling one back for the Wearsiders, but his deflected shot sailed wide.
There was no way back for the home side after Wales international Cotterill's third, and although Roy O'Donovan clipped the bar with a late overhead kick, it will have been little consolation for four-time FA Cup winner Keane.
Sunderland: Gordon, McShane, Nosworthy, Evans, Collins, O'Donovan, Whitehead (Leadbitter 58), Kavanagh, Richardson (Connolly 74), Murphy, Waghorn (Cole 58).
Subs Not Used: Fulop, Anderson.
Wigan: Pollitt, Boyce, Scharner, Granqvist, Kilbane, Olembe, Koumas, Skoko, Taylor (Cotterill 15), Heskey (Brown 72), Sibierski (Aghahowa 42).
Subs Not Used: Kirkland, Valencia.
Goals: Scharner 19, McShane 56 og, Cotterill 76.
Ref: Mike Riley (Yorkshire).
BBC Sport Player Rater man of the match: Wigan's Granqvist 7.75 (on 90 minutes).
Please note that you can still give the players marks out of 10 on BBC Sport's Player Rater after the match has finished.