Cardiff City 1 West Brom 0 - match report and pictures
Peter Whittingham returned to haunt Albion once more and ramp up the pressure on boss Steve Clarke.
The former Villa midfielder scored for his third consecutive game against the Baggies to inflict a fourth straight defeat on the visiting side.
Whittingham headed home Craig Noone's 65th minute cross to decide a largely disappointing game in the Welsh capital.
Gareth McAuley had almost put Albion ahead but saw his shot blocked on the line, while Shane Long was denied a late leveller by an excellent David Marshall save.
But in truth they were isolated moments in another poor performance from the visitors, who have now just won once in the last ten games.
Next weekend's home game with Hull has taken on even greater importance.
Clarke made two changes to the starting line-up with Jonas Olsson returning in place of Diego Lugano, while Long was handed the start up front as Victor Anichebe dropped to the bench.
The hosts were into their stride from the word go and visiting keeper Boaz Myhill was called into action as early as the third minute when he saved Gary Medel's free-kick. From the corner, Ashley Theophile-Catherine saw an effort blocked before Medel fizzed an effort over the bar.
Moments later the hosts were appealing for a penalty when Craig Noone's cross struck Claudio Yacob but referee Howard Webb rightly waved the appeals away.
Albion weathered the onslaught but were indebted to Billy Jones goal-saving header to clear a Theophile-Catherine cross which looked set to present Peter Whittingham with a tap-in. Steven Caulker then missed a great chance to put the hosts ahead when he side-footed a Whittingham corner wide after being left unmarked at the far post.
The visitors showed little in the attacking third and the most nervous moment for Cardiff in the opening half came of their own making, when Ben Turner's poor header back to keeper Marshall created chaos and a passage of play which ended with full-back Andrew Taylor deflecting the ball into the keeper's arms.
Caulker had to be alert to clear a Brunt free-kick which looked destined to reach McAuley at the far post but it was an otherwise comfortable half for the hosts defensively.
The second period again began with a Cardiff free-kick, this time hit by Whittingham and held by Myhill following a slight deflection off the wall.
But it was Albion then came the closest of either team to opening the scoring when McAuley was denied by Medel on the line, after Yacob's mis-hit shot from Amalfitano's cross found him unmarked at the far post. Jonas Olsson just failed to scramble home the loose ball in the ensuing chaos.
The visitors appeared to be growing more and more into the game, with Sessegnon shooting over from distance.
But with 25 minutes to go they found themselves behind. Former Villa man Whittingham is not known for scoring with his head but was able to get in front of Jones and plant Noone's cross past Myhill and into the bottom corner.
Odemwingie then did his old side a favour by blocking Caulker's goal-bound header as the hosts threatened to add a quick second.
Albion then went close with a deflected Mulumbu shot while Long saw claims for a spot-kick waved away after tumbling under a Turner challenge.
Clarke introduced Sinclair and Berahino in search of an equaliser but it was the hosts who next went closest when Jordon Mutch drilled a shot inches over the bar.
Long was inches away from connecting with an Olsson knockdown two yards out as Albion kept pushing. The Irish striker was then denied by a brilliant save from Marhsall, who somehow pushed his point blank header round the post.
Sessegnon then sliced horribly wide in injury time as Albion slumped again.