Oxford United beat Albion 2-1 at the Kassam Stadium on Saturday afternoon.
Stan Mills and Will Lankshear goals - despite an Ollie Bostock strike - handed the U’s the Sky Bet Championship points.
The visitors couldn’t find an early breakthrough during a bright start - and they were made to pay for it on the 14-minute mark, when Oxford’s Mills headed home their first chance from a corner.
Things got worse midway through the half, too. Former Hawthorns loanee Lankshear added a second as he converted another United set-piece, leaving the Baggies in a really tough spot.
Substitute Bostock - who replaced the injured Mikey Johnston - did pull one back before the break, though. The winger’s deflected, long-range effort wrong-footed Jamie Cumming and gave him his first Albion goal, and his team a lifeline.
Following the restart, Josh Maja had a tame header comfortably saved and the wall blocked Jed Wallace’s free-kick.
Daryl Dike and Jamaldeen Jimoh-Aloba - and later Danny Imray and Aune Heggebø - were all introduced to try and get Albion level.
Heggebø saw a flick gathered with the game entering its final 10 minutes, while Krystian Bielik also nodded narrowly wide.
Max O’Leary kept out Aidomo Emakhu’s finish down the other end in a rare Oxford attack - but ultimately neither team managed to net and United claimed the three points.
Albion: O’Leary, Campbell (Imray 75), Bielik, Taylor, Styles, Molumby, Mowatt, Price (Jimoh-Aloba 64), Wallace (Heggebø 75), Maja (Dike 64), Johnston (Bostock 22).
Substitutes: Wallis, Gilchrist, Diakite, Whitwell.