Albion put on a stylish performance at The New Den as they extended their lead at the top of the league to four points.
The Baggies were forced to battle against a physical Milwall side and the elements as goals in each half earned a deserved victory.
Filip Krovinovic scored an excellent goal before the break with Dara O'Shea heading home from a corner to seal the points.
Take a look at all of the action below.