Callum McManaman's 80th-minute goal confirmed victory for the Latics, who twice fell behind during a dramatic contest at The Hawthorns.
The win means that Roberto Martinez's side are just two points from safety with three games left to play this season.
Sports Mole takes a look at the key points on an entertaining afternoon in the Premier League.
On target 11
On target 8
Was the result fair?
West Brom supporters may argue that they deserved a point and for the majority of the game it appeared as though the Baggies had done enough to secure a draw. However, as the game reached its climax, it was Wigan who showed that extra bit of desire to snatch the victory.
West Brom performance
The hosts started the contest well and looked dangerous in attack, with Shane Long and Markus Rosenberg both impressing in the first half. However, Steve Clarke's side seemed to lose their attacking edge in the second half and lost control of the game when Rosenberg and Romelu Lukaku were substituted.
Martinez finds a way to get his side to produce something special every year at this stage of the season. Wigan were not always at their best today but they showed great commitment and a willingness to fight to collect three points from their trip to the West Midlands.
Sports Mole's man of the match:
Shaun Maloney: The 30-year-old once again proved his importance to this Wigan team. The Scottish midfielder was a constant threat to the West Brom defence with his dangerous runs and clever passing in the final third of the pitch. Maloney played a part in all three Wigan goals and his skill to pick out McManaman for the winner was nothing short of magical.
Clarke has done very little wrong in his first season with West Brom and it's difficult to criticise the manager considering the success the Baggies have enjoyed this year. However, his decision to bring off Lukaku and Rosenberg seemed to change the game for all the wrong reasons. Wigan looked more comfortable without the pair on the pitch and the hosts ran out of ideas late on in the game.
Lee Probert had a very good game this afternoon. The man in the middle let the game flow and showed good common sense throughout the contest. Each side had an appeal for a penalty rejected but Probert can be happy with his display on today.
West Brom: The Baggies make the journey to the Etihad Stadium to face Manchester City on Tuesday evening.
Wigan: Martinez and his team welcome Swansea City to the DW Stadium on Tuesday as they look to claim another crucial victory.