West Brom moved up to third in the Championship as Jeremy Sarmiento's fabulous second-half strike proved the difference at Cardiff City.
Sarmiento came closest to scoring in a goalless first half with a shot that hit the post after a swift counter-attack from the visitors.
The Ecuadorian attacking midfielder, on loan from Brighton, then put the Baggies ahead with a fine whipped effort which dipped and curled into the far corner.
Cardiff struggled to create many genuine chances as they searched for an equaliser and were limited to long-range shots from Josh Bowler and Rubin Colwill.