A LATE winner from Callum McManaman gave Latics a priceless three points in their battle against relegation.
Latics had twice trailed at the Hawthorns, with Shane Long and Gareth McAuley putting the Baggies in charge.
But equalisers from Arouna Kone and James McArthur - with his first touch after coming on as a second-half substitute - restored parity.
And with time running out, and a draw of no real use to the visitors, Shaun Maloney worked his magic down the left and McManaman stabbed home to the delight of the 1,200 travelling supporters behind the goal.
The victory puts Latics on 35 points from their 35 games played, and means they can move out of the bottom three with a win against Swansea on Tuesday.
Latics: Robles; Boyce, Watson, Scharner; Stam, McCarthy, Gomez, Beausejour; McManaman, Maloney, Kone.
Subs: Al Habsi, Caldwell, Golobart (for Stam, 56), Espinoza (for Beausejour, 74), Henriquez, McArthur (for Gomez, 56), Di Santo.
West Brom: Foster; Jones, Olsson, McAuley, Ridgewell; Mulumbu, Dorrans, Yacob; Rosenberg, Lukaku, Long.
Subs: Myhill, Morrison, Thomas (for Rosenberg, 66), Odemwingie, Dawson, Tamas (for Lukaku, 66), Brown (for Mulumbu, 86).