Wigan Athletic dominated the opening proceedings, and Ben Watson - making his first appearance for the Latics since November - was at the centre of much of the visitors' play.
However, it was the home side who opened the scoring on the half-hour mark, after good work between West Brom's forwards. Romelu Lukaku played a ball into the right-hand channel for Markus Rosenberg, who squared the ball for Shane Long, who slid in to knock the ball home.
© Clint Hughes / PA Photos
The Latics showed the spirit that has rescued them from many a relegation battle as they fought back to equalise yet again.
© PA Photos
With 10 minutes left on the clock, Shaun Maloney beat a couple of defenders, before pulling the ball back for Callum McManaman to tap home from six yards out.
In the final five minutes of added time, James McArthur cleared the ball off the line to ensure Wigan held on to a three vital points in the battle for survival.