Albion couldn’t have had a better start as after just two minutes Fraser Forster fumbled a Marc Cucurella cross and Danny Welbeck forced the ball home to give Albion an early lead.
Southampton hit the post through Tino Livramento and Che Adams almost scored from the rebound as the ball appeared to rebound off the backside of Robert Sanchez.
Neal Maupay had the ball in the net from a corner but was adjudged offside.
An innocuous-looking injury to Livramento delayed play for a while as he was unfortunately stretchered off.
Then seconds before half time Welbeck linked up with Leandro Trossard who fired in a cross which Mohammed Salisu turned into his own net under pressure from the aforementioned Welbeck.
In the five minutes of added time, a James Ward-Prowse free kick eluded the Albion wall and Sanchez to halve the deficit.
