West Brom scored three first-half goals as they swept aside a Burnley team that is struggling away from home this season.
The Clarets, with only one point from 15 on their travels, got off to an awful start when Matt Phillips turned four yards out and fired high past keeper Tom Heaton.
Like Phillips, James Morrison also scored for a second successive game when he ran on to Salomon Rondon's pass and curled a low shot inside Heaton's near post.
And the impressive Phillips provided the cross for the third, which was tapped in at the far post by Darren Fletcher for his first of the season.