A CLINT Dempsey strike four minutes before half time set the Whites on their way to a much-needed first away win of the season.
Moussa Dembele finished off the home side four minutes from time, consigning the struggling hosts to a seventh defeat in a row.
Dempsey (pictured) was found in space by Bobby Zamora for the opener and thereafter, the Whites soaked up home side pressure - only rarely looking like conceding.
The two goals doubled Fulham's total away from home in the Premier League, with Dempsey equalling Brian McBrides record total of 36 goals for an American in the top flight.
Wigan had the better chances early on and hit the woodwork through Victor Moses and Maynor Figueroa, but Zamora also hit the crossbar.
But Wigan's top scorer of last season, Hugo Rodallega, has failed to score in seven games this season and never looked confident that he would end his goal drought.
The Latics' big chance came when Moses hit the angle of post and crossbar from outside the box after outmuscling John Arne Riise.
Wigan continued to press and Figueroa hit the post with a curling effort from 30 yards out but minutes later the defender gifted Sidwell the ball on the halfway line and he found Dembele, who charged forward and slotted home.
"We deserved to win because over the season we should have picked up four or five more points, Argued boss Martin Jol.
"We changed it around and put Moussa Dembele in midfield. I thought Moussa deserved to score, he was terrific.
"He is so gifted. The next step is for him to score goals. He has all the talent in the world."