STEPHANE Sessegnon came back to haunt his former employers by opening the scoring on his Albion debut to help earn his new club their first Barclays Premier League win of the campaign.
Less than three weeks since making the switch from Wearside – and having scored in both encounters for the Black Cats in games between the two sides last term – the Benin international put his ex-team-mates to the sword in the 20th minute.
His strike laid the foundations for a well-earned three points that were sealed by Liam Ridgewell’s second Baggies goal 14 minutes from time.
And Morgan Amalfitano put the icing on the cake of a man-of-the-match performance with a third goal three minutes into stoppage time.
The hosts produced a slick performance as Steve Clarke’s new signings clicked into gear, based on another solid display by the rearguard, which brought a second clean sheet in four games.
And the Mackems will be sick of the sight of Albion as they slumped to a seventh defeat in eight games between the two teams.
Sessegnon was handed his Baggies bow as Clarke made three changes.
James Morrison and Scott Sinclair were also drafted in, with Victor Anichebe and Claudio Yacob dropping to the bench and Chris Brunt missing out due to a groin injury.
Paolo Di Canio made four changes to the Black Cats team that lost 3-1 at home to Arsenal last weekend, with Craig Gardner, John O’Shea, Emanuele Giaccherini and Fabio Borini restored to the starting XI.
The Baggies showed early endeavour to earn a corner and Morrison was unfortunate to see his near-post header from Amalfitano’s corner deflect just over off a Black Cats defender.
After weathering a period of pressure from the visitors, it was the Baggies who snatched the lead in the 20th minute.
Sessegnon spread the ball out to Amalfitano on the right and he swung in a near-post cross that Sinclair prodded goalwards. Kieren Westwood did well to beat it out but Sessegnon was on hand to knock home the rebound.
He was mobbed by his new team-mates – but the 29-year-old ace did not celebrate out of respect to his former club.
Craig Gardner dispossessed Youssouf Mulumbu in the 27th minute and burst into the box before crossing to the back post to find Adam Johnson in space.
The former Middlesbrough winger unleashed a fierce low drive that Jonas Olsson got the faintest of touches on to put it into the side-netting.
Two minutes later, a slick move from the hosts saw Mulumbu find Amalfitano on the right side of the penalty area and he cut inside Jack Colback before seeing his strike diverted onto the bar by a Sunderland leg.
On 33, good work by Amalfitano saw him dispossess Colback and the ball sprang for Nicolas Anelka, whose low cross was just gathered by Westwood before Sinclair could get to it inside the six-yard box.
Di Canio made a change at the break, with Giaccherini making way for Charis Mavrias. Just before the hour-mark, Jozy Altidore replaced Borini for the Black Cats.
Moments later, Sessegnon showed good strength to roll Modibo Diakite in the box before volleying over from 15 yards.
Albion had a lucky escape in the 65th minute when Colback centred for Altidore and the USA international’s goalbound shot deflected inches wide of the right-hand post off Olsson.
Two minutes later, Billy Jones crossed at the other end and Anelka was unfortunate to see his header clip off Johnson and out for a corner rather than nestle in the net.
That was the Frenchman’s last action as he departed to be replaced by Anichebe, while Yacob came on for Sinclair.
Sunderland completed their substitutions when Gardner made way for Lee Cattermole on 69.
The visitors missed a glorious chance to level in the 72nd minute when Steven Fletcher volleyed high over the bar from ten yards from Johnson’s cross.
The former Wolves man was injured in the process after colliding with Jones and was forced off, leaving the Black Cats with ten men, having used all their subs.
The Baggies sealed the points in the 76th minute as Amalfitano turned creator again.
The deadline-day loan signing delivered another telling cross from the right, which Westwood could only half-punch away.
Ridgewell pounced on the loose ball and volleyed home from ten yards despite Westwood getting a finger-tip to the ball.
The Baggies continued to pose a threat until the final whistle, with Morrison twice unlucky not to get on the end of Ridgewell crosses.
And in stoppage-time, Amalfitano wrapped up the victory with a pure strike across the keeper from Anichebe’s pass to make it 3-0.
ALBION (4-4-1-1): Myhill; Jones, McAuley, Olsson, Ridgewell; Amalfitano, Mulumbu, Morrison, Sinclair (Yacob 68); Sessegnon (Berahino 89); Anelka (Anichebe 68). Subs not used: Camp (gk), Rosenberg, Lugano, Popov.
SUNDERLAND (4-4-2): Westwood; Celustka, Diakite, O’Shea, Colback; Johnson, Gardner (Cattermole 69), Ki, Giaccherini (Mavrias HT); Fletcher, Borini (Altidore 59). Subs not used: Mannone (gk), Ba, Cuellar, Dong-won.
GOALS: ALBION – Sessegnon (20), Ridgewell (76), Amalfitano (90+3).
BOOKINGS: SUNDERLAND – Colback (foul 28), Ki (foul 35).
REFEREE: P Dowd (Staffordshire).
ALBION STARMAN: Morgan Amalfitano.