Birmingham City ended Albion’s four-match unbeaten run by beating them 1-0 in the Sky Bet Championship on Sunday afternoon.
Following a goalless first period, Blues took a 67th minute lead via Lyle Taylor’s penalty.
And The Baggies were unable to find a leveller in the second city as the hosts took all three points.
Steve Bruce named an unchanged XI for the fifth consecutive game on his return to St. Andrew’s.
During a first half of few chances for either side, Albion had a strong penalty shout waved away by the referee and Alex Mowatt smashed a volley over.
Clear-cut opportunities were hard to come by despite the visitors getting in decent positions, and Blues only really presented a threat through Marc Roberts’ long throws – which the Baggies dealt well with.
After the interval Birmingham managed to break the deadlock, Conor Townsend being penalised for a handball and Taylor converting from the spot.
Bruce responded, bringing on Grady Diangana, Andy Carroll and Adam Reach, but Albion just couldn’t seem to craft an equaliser.
Callum Robinson was foiled when in by Kristian Pedersen’s goal-saving block, and with time ticking away Carroll headed a golden chance narrowly wide.
Eight minutes of stoppage gave the Baggies one final chance, however Blues held firm to earn the derby day win.
Albion: Johnstone; Furlong, Ajayi, Bartley, Clarke, Townsend (Reach 76); Gardner-Hickman (Diangana 60), Livermore, Mowatt; Robinson, Grant (Carroll 68).
Substitutes: Button, Kipré, O’Shea, Molumby.