Wigan - Free-scoring Chelsea hit six goals for the second Premier League game in succession to heap more misery on Wigan.
The hosts, who were embarrassingly beaten 4-0 at home by newcomers Blackpool in their opening game, made an encouraging start but still found themselves behind at half time.
Goalkeeper Chris Kirkland made a fine save from Frank Lampard but Florent Malouda was on hand to tap in the rebound in the 34th minute.
Nicolas Anelka, in the week his France career was effectively ended by an 18-match ban, made it 2-0 with a clinical finish in the 48th and he put the game to bed four minutes later with a close-range header, despite Wigan's claims of offside.
Didier Drogba set up Salomon Kalou for the fourth before Kalou got his second in the 90th.
Yossi Benayoun slotted home his first Chelsea goal in injury time to complete the rout and leave the Blues, which also thrashed West Brom 6-0 in its opening game, top of the Premier League table.