Peter Odemwingie increased the pressure on Southampton boss Nigel Adkins as his two goals propelled West Brom into fifth spot in the Barclays Premier League.
Adkins' side remain rooted to the foot of the table after a fifth successive away defeat and they have now conceded 28 goals in 10 league matches.
But these are halcyon days for the Baggies and they bounced back from heartbreaking injury time defeats against Manchester City and Newcastle thanks to a goal in each half from Odemwingie.
It was their fifth victory in six home matches and, although not at their best, they still contained too much firepower for the Saints.
Odemwingie and the tireless Shane Long posed plenty of problems up front while Youssouf Mulumbu bossed the midfield department.
Albion fans taunted Adkins, who has led Southampton to successive promotions, with chants of 'you're getting sacked in the morning'.
And, although the visitors showed plenty of promise in spells, their leaky defence is undermining their attacking threat.
Southampton axed keeper Artur Boruc who has been the subject of a club investigation after allegedly throwing a water bottle into the crowd during the home league game with Tottenham.
Albion began positively and a fine pass from Odemwingie picked out the run of Long into the Saints box.
But the Baggies leading scorer opted to cut the ball back across the danger area rather than shoot.
Billy Jones became the first player to be yellow carded after 10 minutes for a high challenge which caught the back of Southampton skipper Adam Lallana.
Rickie Lambert had the first attempt on goal and his low drive from a narrow angle contained plenty of power but was held onto by West Brom keeper Ben Foster.
Albion retaliated and a low shot from Odemwingie took a deflection off Zoltan Gera and flew over the Saints crossbar.
The home side started to look more threatening and it needed a last ditch tackle from Morgan Schneiderlin to deny Long after Jonas Olsson had headed a Graham Dorrans free-kick back across goal.
Odemwingie flashed a low 25 yard shot inches wide in a swift Albion counter-attack after Foster had gathered Lambert's header from a Gaston Ramirez centre.
But the Nigeria international broke the deadlock in controversial fashion in the 36th minute.
The impressive Mulumbu released Odemwingie whose left-footed shot contained plenty of power but took a deflection off Maya Yoshida as it flew past Saints keeper Paulo Gazzaniga.
But TV replays also showed that Odemwingie had appeared to handle the ball in the build-up.
Gazzaniga did well to block a close range effort from Long and Albion appealed in vain for a penalty for handball when Schneiderlin blocked the follow-up attempt from Odemwingie.
Southampton started the second half on the offensive and a shot on the turn from Lambert struck the bar with Foster well beaten.
Foster cut out a dangerous cross from Daniel Fox as the visitors pressed for an equaliser.
But after 60 minutes Odemwingie doubled Albion's lead with a clinical finish.
Left-back Liam Ridgewell's long pass found Long who held the ball up, cut inside and floated over an inviting centre which Odemwingie headed home from close range.
The Baggies could have increased their lead with skipper Chris Brunt volleying just wide at close range from a cross by fellow substitute Romelu Lukaku.
Yoshida headed just wide in a late Southampton rally but Albion held on for a comfortable win.