Albion were beaten 1-0 by Middlesbrough at the Riverside Stadium on Saturday afternoon.
Morgan Rogers’ first-half goal handed Boro all three Sky Bet Championship points.
The Baggies will have a chance to bounce back Boxing Day, when they host Norwich City.
Carlos Corberán named an unchanged XI in Middlesbrough, and was able to welcome John Swift back into his matchday squad.
The hosts forced a good save from Alex Palmer within the opening three minutes, Isaiah Jones in on goal only to see his low shot well stopped.
Albion went close themselves midway through the half, Kyle Bartley’s looping header hitting the outside of the post before Darnell Furlong then saw his powerful effort pushed over by goalkeeper Tom Glover.
However, Middlesbrough switched the momentum their way and - following a strong spell - found the first goal five minutes ahead of the break. Albion Academy graduate Rogers was the one to net, converting a low cross to give the home side a 1-0 advantage.
The Baggies managed to stay in the game despite a Boro onslaught after half-time, Rav van den Berg having a goal chalked off for offside and Palmer superbly keeping out Rogers’ poke at close-range.
Sam Greenwood then skied a golden opportunity just a couple of yards out - and Albion’s goalkeeper denied Jones again - as the visitors continued to ride their luck.
Corberán tried to turn the tide, using all five substitutions available, but his team couldn’t salvage anything during the final stages and were sent home with a defeat.
Albion: Palmer; Furlong (Pipa 80), Bartley (Ajayi 73), Kipre, Townsend; Yokuslu (Molumby 73), Mowatt; Wallace (Swift 73), Sarmiento (Fellows 59), Diangana; Thomas-Asante.
Substitutes: Griffiths, Pieters, Chalobah, Reach.