Andy Johnson opened his Fulham account with two goals to continue Wigan's freefall down the Barclays Premier League.
The England striker, a £10.5million summer signing from Everton, struck in each half to condemn Wigan to their fourth successive defeat.
Controversy surrounded the opener — Johnson's 100th league goal — as he looked a yard off-side, but the second was well taken with Jimmy Bullard the provider.
Bullard's astute free-kick created the space for Johnson and it was a welcome highlight for the 30-year-old, who otherwise endured a disappointing game against his former club.
The victory was Fulham's first in seven matches and helped ease their own concerns after slipping towards the bottom of the table.
Wigan headed in the opposite direction with their dismal run making their unbeaten progress through September seem like a distant memory.
Titus Bramble was dropped to the bench in response to the weekend's 4-0 drubbing by Aston Villa, while Antonio Valencia returned from suspension, but the changes failed to halt the slump.
Conceding a glut of early possession, Wigan came under heavy pressure and paid the price as Johnson sent Fulham ahead in the 10th minute. Replays suggested Johnson was off-side but he wasted little time celebrating his first goal for Fulham, lifting his shirt to reveal a vest trumpeting his 100th league strike.