ALBION fell to a 3-0 defeat against runaway Premier League leaders Manchester City on Wednesday evening.
Fernandinho handed dominant City a 19th-minute lead before Kevin De Bruyne, who pulled the strings for the hosts, doubled their advantage midway through the second half at the Etihad Stadium.
Ben Foster made a string of excellent saves for the Baggies, who handed January loan signing Daniel Sturridge his debut for the latter stages of the encounter.
Alan Pardew's side, who tasted defeat for only the second time in eight matches, now turn their focus to Saturday's league clash against Southampton at The Hawthorns.
Albion, captained by Gareth McAuley, made six changes from last weekend's superb FA Cup victory at Liverpool - captain Jonny Evans, Kieran Gibbs, Jake Livermore and Hal Robson-Kanu missing out due to injury.
Ben Foster had to be alert to make the first of several fine saves at his near post to keep out De Bruyne's strike from the angle of the penalty area.
The Baggies found themselves behind in the 19th minute as De Bruyne's inch-perfect ball sent in Fernandinho and he slotted past Foster.
Albion's No.1 stood up well to save from the lively De Bruyne when he was slotted clean through before the Belgium international, at the heart of City's play, fired just over from 18 yards.
Gareth Barry was introduced for the injured Grzegorz Krychowiak just after the half-hour mark, receiving a warm reception from his former club upon his 650th Premier League appearance.
De Bruyne was at it again to force another super save from Foster before the break, with Raheem Sterling curling an opening off target and Foster reacting quickly to keep out Sergio Aguero's instinctive backheel shortly after the restart.
Head Coach Pardew turned to Matt Phillips in the 55th minute but it was Foster who was again at the centre of the action, saving full stretch from Bernardo Silva.
But there was nothing he could do in the 68th minute as De Bruyne broke from midfield, exchanged a one-two with Sterling and slotted home to double City's advantage.
De Bruyne almost found the top corner with an audacious strike from near the halfway line.
Sturridge was introduced for his Baggies bow in the 78th minute. But it was Foster who was in superb form again late on to deny City substitute Brahim Diaz.
Albion's Liverpool loanee could have halved the deficit ten minutes after entering the fray but couldn't convert from a tight angle.
And City made him pay in the following minute, Sergio Aguero dinking the ball over Foster to wrap up the points.
ALBION: Foster, Dawson, McAuley (c), Hegazi, Nyom, Field (Phillips 55), Krychowiak (Barry 33), Yacob, McClean, Rodriguez, Rondon (Sturridge 78).
Subs: Myhill, Brunt, Harper, Burke, Phillips.