Southampton suffered their first away defeat since early December as Saido Berahino’s early goal earned West Brom a 1-0 win.
The narrow reverse was the first loss on the road for Ronald Koeman’s side since they were beaten by the same scoreline at Burnley.
Berahino’s goal came inside the opening 90 seconds, as the Baggies frontman fired home a loose ball from the edge of the box, condemning Saints to a third game without a win.
Following the defeat to Liverpool at St Mary’s, Koeman made five changes to the side as Ryan Bertrand and Florin Gardos came into a back five, with Morgan Schneiderlin, making his first start since returning from injury, back in midfield.
Dušan Tadić and Sadio Mané were also recalled as Koeman switched to a 5-3-2 formation. Steven Davis, James Ward-Prowse, Matt Targett, Eljero Elia and Filip Djuričić all dropped to the bench.
Having fallen behind inside the opening two minutes against Liverpool, it was a frustrating case of déjà vu for Koeman’s side, as Berahino fired past Fraser Forster inside 90 seconds.
A long ball played forward by Chris Brunt was only headed back out as far as Berahino, who left Forster with no chance, finding the top corner superbly.
Saints were finding it difficult to cope with the Baggies and Koeman was forced to bring on Elia in place of Gardos with 25 minutes gone, reverting to a back four with Elia, Tadić and Mané in support of Graziano Pellè.
The switch brought about the first real chance of the game for the visitors. Schneiderlin’s excellent pass out to the right found Mané, who neatly chested the ball past his man, but blazed over from inside the penalty area.
The hosts themselves almost made it 2-0 when Craig Gardner got in behind the defence, but José Fonte did well to snuff out the danger and Forster was able to claim the loose ball.
Saints upped the tempo and twice went close on the hour mark to finding an equaliser.
Schneiderlin went close with a free-kick from a tight angle that flashed just wide of Ben Foster’s goal, before Elia headed over the bar.
Elia was involved again as Saints got in behind moments later. The Dutchman’s pass found Bertrand but Pellè was unable to turn home the cross as Brunt’s touch took it wide of the post.
Darren Fletcher had a good chance for the home side as the game approached the final 15 minutes, but he blazed over from close range.
Pellè then had another opportunity to get back among the goals as Schneiderlin headed Mané’s cross towards goal, but the striker was unable to get enough power into the shot and Foster held comfortably.
Substitute Elia almost equalised with the last kick of the game but he blazed wide of Foster’s goal as Saints failed to find a way through against the Baggies.
West Bromwich Albion: Ben Foster, Craig Dawson, Gareth McAuley, Joleon Lescott, Chris Brunt, James Morrison (Stephane Sessegnon 72), Claudio Yacob, Darren Fletcher (c), Craig Gardner, Brown Ideye (Chris Baird 88), Saido Berahino (Youssouf Mulumbu 56).
Unused substitutes: Boaz Myhill (GK), Andre Wisdom, Jonas Olsson, Callum McManaman,
Goals: Saido Berahino (2)
Booked: Ben Foster (62), Stephane Sessegnon (82)
Southampton: Fraser Forster, Nathaniel Clyne, José Fonte (c), Maya Yoshida, Florin Gardos (Eljero Elia 25), Ryan Bertrand, Morgan Schneiderlin, Victor Wanyama (Steven Davis 46), Sadio Mané, Dušan Tadić (Shane Long 74), Graziano Pellè.
Unused substitutes: Kelvin Davis (GK), Matt Targett, James Ward-Prowse, Filip Djuričić.
Booked: Victor Wanyama (25)