Wigan missed the opportunity to lift themselves out of the bottom three as Paul Scharner earned West Brom a 1-1 draw at the DW Stadium.
However there was nothing he could do about James McArthur's opening goal as a Victor Moses cross struck Billy Jones and allowed the Scottish midfielder to poke it over the line.
Scharner came back to haunt his old side nine minutes later as he headed a Chris Brunt corner past Ali Al Habsi.
Swansea completed their first run of three successive Premier League victories by beating Fulham 3-0 at Craven Cottage on Saturday.
The Swans took the lead through Gylfi Sigurdsson's header before the Icelander netted another in the second half after a lightning counter. Joe Allen added further gloss to the scoreline with a third.
Manchester United cemented their position on top of the Premier League and sent Wolves to the bottom with a 5-0 thrashing at Molineux.
Sir Alex Ferguson's men were already a goal to the good after Jonny Evans opened the scoring when Ronald Zubar was sent off for a second yellow card shortly before the end of the first half.
Antonio Valencia and Danny Welbeck made it 3-0 with a quickfire double before the break and Javier Hernandez's second-half brace put a gloss on a dominant performance which has put the champions four points clear of title rivals Manchester City.
Newcastle United got their Europa League bid back on track with a 1-0 victory against Norwich City at the Sports Direct Arena.
The Magpies moved within two points of Chelsea in fifth place thanks to Papiss Cisse's solitary strike, during Alan Pardew's 500th career league game as manager.
