Moses the hero for Latics
Victor Moses stepped off the bench to end Wigan's run of five Barclays Premier League games without a win in a 1-0 triumph.
The former Crystal Palace midfielder scored the winner against West Brom in the 70th minute after being released by Charles N'Zogbia.
Moses rifled a shot beyond Scott Carson and into the corner for his first league goal of the season.
The home side went close in the second minute but midfielder Tom Cleverley, on loan from Manchester United, saw his effort turned away on the line by Pablo Ibanez.
West Brom stepped up the pace and Peter Odemwingie raced to the byline in the 26th minute. He cut the ball back into the area but there was no-one on hand to take advantage and Antolin Alcaraz made the clearance.
Back came Wigan and Alcaraz escaped his marker in the 35th minute when Charles N'Zogbia floated in a corner, only to head over from a good position.
West Brom appealed for a penalty in the 55th minute when Caldwell tripped Odemwingie but referee Anthony Taylor awarded a free-kick on the edge of the area and Chris Brunt's effort came back off the wall.
Wigan made the vital breakthrough in the 70th minute when 19-year-old Moses showed remarkable maturity in front of goal to steer his effort beyond West Brom goalkeeper Scott Carson and into the corner.
The home side should have added a second goal in the 82nd minute but substitute Franco Di Santo - clear on goal - dragged his effort wide.
Marc-Antoine Fortune almost equalised at the end but Wigan goalkeeper Ali Al Habsi blocked his shot to leave West Brom frustrated.