James Ward-Prowse scored twice in the first-half as Southampton secured a 3-0 victory over West Brom at St Mary's.
The Saints midfielder dispatched a curling 25-yard free-kick to open the scoring after five minutes on Saturday afternoon, before doubling the lead from the penalty spot ten minutes before half-time.
West Brom went close through Victor Anichebe's volley midway through the second half, but substitute Dusan Tadic sealed the three points with an excellent finish from close range.
The two sides started Saturday level on points, but the victory sees Southampton move up to 10th while the Baggies remain 13th after their fourth away league defeat of the season.
There was a feel-good factor around St Mary's before kick-off after the club announced the signing of striker Charlie Austin - who watched from the stands - in the build-up, and the Saints started the brighter, going ahead early on through Ward-Prowse.
The Saints midfielder lined up a free-kick after Sadio Mane was fouled 25 yards from goal, and whipped the ball over the wall and past Myhill, giving the West Brom goalkeeper little chance.
Southampton enjoyed 80 per cent possession in the opening exchanges on a pitch hosting its third game in eight days, but the Baggies almost levelled after 10 minutes. Craig Gardner was left unmarked and the midfielder flicked James McClean's cross just wide with Fraser Forster rooted to the spot.
With Ronald Koeman's side on the front foot, Pulis tweaked his formation, bringing Stephane Sessegnon alongside Anichebe on the half-hour mark, but five minutes later Southampton doubled their lead.
Ward-Prowse had scored just once in his previous 92 league appearances, but got his second of the afternoon from the penalty spot after good work from Matt Targett.
The defender, who was impressive against Watford in midweek, played a neat one-two with Shane Long, and as he looked to retrieve the return pass, was bundled over by Craig Dawson.
Referee Martin Atkinson had turned down a West Brom penalty appeal shortly before, although replays showed the challenge on Gardner was outside the box, and Ward-Prowse made no mistake when given the opportunity for Southampton.
The Saints could have made it three two minutes later, but Targett's low drive was cleared off the line by James McClean.
Tony Pulis made a double change at the interval, bringing on Salomon Rondon and Chris Brunt, and West Brom initially improved.
The lively combination of Long and Mane continued to offer an outlet for the hosts, but the latter could only manage to guide his shot wide at full stretch.
And the away side almost halved the deficit through Anichebe with 25 minutes remaining. The Baggies striker took the ball on his chest before firing a low volley from the edge of the box narrowly past the far post.
Mane was withdrawn for Tadic in the closing stages, and for the second time in as many games, the Serb substitute sealed the points.
Steven Davis, who was excellent all afternoon, led the counter-attack after latching on to Long's flick and driving into the West Brom half. The midfielder cut inside and slipped a disguised reverse pass into the path of Tadic, who fired across the face of goal and into the far corner.
Pulis ended the game with Saido Berahino, Rondon and Anichebe in attack, but it wasn't a performance to remember as his side failed to test Forster once.
The Southampton 'keeper has clean sheets in both games since his return, but after three consecutive home league wins, his side faces a tougher challenge with trips to Old Trafford and the Emirates Stadium to come next.
West Brom host Aston Villa at The Hawthorns next weekend, but first must travel to Bristol City for their FA Cup third-round replay on Tuesday night.
Player ratings
Southampton: Forster (6), Cedric (7), Fonte (7), Van Dijk (7), Bertrand (7), Targett (7), Ward-Prowse (8), Wanyama (8), Davis (8), Long (7), Mane (7)
Subs used: Tadic (7), Romeu (6), Martina (6)
West Brom: Myhill (6), Olsson (6), Yacob (6), Evans (6), Gardner (6), Anichebe (6), McClean (6), McAuley (5), Fletcher (6), Dawson (5), Sessegnon (5)
Subs used: Brunt (6), Berahino (6), Rondon (6)
Man of the match: James Ward-Prowse