Charlie Austin kept his nerve to keep Albion top of the Championship after a hard fought 2-1 victory over Sheffield Wednesday.
Albion opened the scoring in the first half when Hal Robson-Kanu continued his purple patch in front of goal after a delightful pass by Matheus Pereria.
Wednesday hit back after the break when former Wolves striker Steven Fletcher scored from the spot after Filipe Krovinovic's error.
But Albion again showed their promotion credentials with another late goal through Austin's spot kick after Pereira had been brought down by Wednesday keeper Kieran Westwood.
Slaven Bilic was forced into two changes with Kronvinovic and Ahmed Hegazi - making his first start of the season - in for the suspended Jake Livermore and Romaine Saywers.
Despite the unfamiliar midfield - with Kronvinovic playing alongside Semi Ajayi - Albion were brighter and Robson-Kanu headed over inside the first minute.
But the visitors grew into the game and threatened on a couple of occassions, without pressing Sam Johnstone into a save.
Wednesday were the better team after the break. After Fletcher's equaliser, the visitors then hit the bar after a free kick.
Bilic rang the changes with Gareth Barry and Chris Brunt called upon to get a grip of the midfield and - not for the first time this season - the subsitutes changed the game.
Subsitute Austin hit the post with a header moments before he grabbed the headlines with his penalty driven into the bottom corner to send Albion five points clear of third-placed Preston.