Birmingham - West Brom beat Stoke City 1-0 on Saturday as James Morrison's early tap-in spoilt the homecoming of Saido Berahino's in his debut for the visitors.
Berahino was booed onto the pitch by home fans angered at their former goal-king's protracted bid to force a move, when he eventually came off the bench with 30 minutes to go.
After three transfer windows where the 23-year-old had tried to get away he joined Stoke last week for £12 million but found himself immediately back at his old team.
Mark Hughes started with Peter Crouch and Marko Arnautovic in attack but to little effect.
Stoke dominated the early play and were relieved by a linesman's off-side flag after Salomon Rondon slotted home on five minutes.
Almost immediately the Baggies raced upfield again as Nacer Chadli's quick thinking through ball set up Morrison to score on six minutes.
Ibrahim Afellay set up Crouch for Stoke on 25 minutes but the sprawling Ben Foster made a decisive save.
The West Brom 'keeper was key again in saving from Arnautovic as Stoke dominated possession while failing to take advantage.
With less than 30 minutes to play Hughes brought on Berahino and Mame Diouf and wile they looked alive Berahino fell over one ball he received sending howls of laughter down from the terraces.
Baggies midfielder Jake Livermore made a crucial clearance on 80 minutes as Arnautovic hesitated when teeing up a shot.
The teams started the day eighth and ninth in the Premier League but West Brom are now seven points ahead on 36 to Stoke's 29 from 24 games.