Albion were beaten 2-0 by Bristol City at The Hawthorns on Tuesday evening.
First-half goals from Joe Williams and Nahki Wells were enough to secure the points for the Robins.
The Baggies are back in Sky Bet Championship action this weekend with a trip to Millwall.
Richard Beale named an unchanged XI from the win against Reading – but had to replace Karlan Grant (illness) with Tom Rogic in the matchday squad.
Neither side created any major chances until the opening goal, which arrived just after the half-hour mark when Williams poked home for the visitors.
Albion did have a good opportunity to equalise, Matty Phillips blazing over despite being well-placed on the edge of the box.
Instead, though, City doubled their advantage on the verge of half-time via Wells’ deft header, giving the Baggies a mountain to climb in the second period.
Beale switched things up by bringing on Jayson Molumby, Tom Rogic and Reyes Cleary as the hosts searched for a way back into the clash.
They had a penalty shout turned away when it looked like a City player had blocked a cross with his arm – and went close through Brandon Thomas-Asante, who saw his header hit the post.
Substitute John Swift also crashed an effort against the crossbar late on, however that’s the closest Albion came to netting and Nigel Pearson’s team ended up victors.
Albion: Palmer; O’Shea, Kelly, Pieters; Phillips (Rogic 59), Livermore (Molumby 45), Gardner-Hickman (Swift 76), Townsend; Wallace, Thomas-Asante, Diangana (Cleary 59).
Substitutes: Button, Furlong, Yokuslu.