Albion were beaten 2-1 by Millwall at The Den on Saturday afternoon.
John Swift’s opener was cancelled out via Callum Styles’ effort in a heated first half – but substitute Tyler Burey’s late winner ensured they took all three Sky Bet Championship points.
The Baggies now have a full week before they return to action next weekend when they host Sheffield United in B71.
Richard Beale made six changes to the starting XI, bringing in Kyle Bartley, Darnell Furlong, Adam Reach, Okay Yokuslu, Swift and Karlan Grant.
And it was Albion who took the lead on the 20-minute mark. Former Millwall man Jed Wallace picked out Swift with a pinpoint cross, and the attacking midfielder converted for his third of the season.
They were, however, pegged back shortly ahead of half-time by Styles’ deflected strike – the Hungarian international finding the net to ensure it was 1-1 at the break.
The home team made a stronger start to the second period and came close to scoring a few times, with Tom Bradshaw missing a golden close-range opportunity and Burey curling narrowly wide. The latter then had the ball in the net 21 minutes from time – but looked across to see the assistant referee’s flag raised.
Things were made harder for the visitors late into the game when Kyle Bartley picked up a second yellow card, reducing Albion to 10-men.
And Millwall grabbed the victory during stoppage time through Burey’s finish, condemning the Baggies to a second straight league defeat.
Albion: Palmer; O’Shea, Bartley, Pieters (Townsend 64); Furlong, Yokuslu, Swift (Rogic 75), Gardner-Hickman (Molumby 75); Wallace, Grant (Phillips 84).
Substitutes: Button, Diangana, Cleary.