Wigan recorded a vital first win in six games against West Brom on Saturday to lift it out of the Premier League relegation zone.
Substitute Victor Moses scored the only goal in the 70th minute after a cross from Charles N'Zogbia.
Both teams created chances in a lively, close-fought match. Tom Cleverly almost opened the scoring in the second minute but West Brom defender Pablo Ibanez cleared off the line.
N'Zogbia then lost his footing after being put through on goal by Hugo Rodallega while West Brom's Nigeria striker Peter Odemwingie shot wide.
Chris Brunt and James Morrison drew saves from Wigan goalkeeper Ali Al Habsi, and the visitors felt they should have had a penalty in the 55th when Steven Caldwell tripped Odemwingie on the edge of the area. Referee Anthony Taylor chose to award a freekick, which Brunt fired into the wall.
After Moses had coolly slotted the opener, Franco Di Santo should have made the points safe for Wigan in the 82nd but he dragged his shot wide after being put through clean through on goal.
The result moves Wigan up to 16th and means that West Brom, which lies 11th, has now gone four games without a win.
