James Morrison came back from injury to set up West Brom's first away win of the Premier League season as his powerful header helped the visitors sink Wigan at the DW Stadium.
Scotland midfielder Morrison was forced to miss the Baggies' win over Southampton on Monday night, due to a hamstring problem, but he returned to help inspire Steve Clarke's men to three points which keeps them firmly rooted in the league's top six.
Morrison met a cross from Chris Brunt to head an unstoppable opener past Ali Al Habsi, before a Gary Caldwell own goal put the Baggies in command. Arouna Kone reduced the deficit and the Latics piled on the pressure but could not claim a point.
The visitors started with Peter Odemwingie on the bench despite his two-goal haul against Southampton, but his replacement Romelu Lukaku quickly made his presence felt with a surging forward run.
Maynor Figueroa drilled a low long-range shot just wide for the home side in the fifth minute and James McCarthy's persistence also fashioned an early chance after he robbed Claudio Yacob and pressed forward.
And it took Baggies goalkeeper Boaz Myhill - in for his first senior Baggies game in 21 months due to injury to Ben Foster - nine minutes to prove worthy of his call-up as he pulled off a superb save to deny Ben Watson.
The visitors slowly began to find their rhythm, with the alert Al Habsi racing from his goal to deny Lukaku, as the home side, who continued to shade possession in an open game, were too often let down by a stray final ball.
More scrappy play from the hosts almost cost them dear after 26 minutes when indecision in defence forced Al Habsi to once again come out and save from Morrison then dive on the loose ball as Lukaku waited to pounce.
But there was nothing scrappy about the opener on the half-hour as Brunt flung in a precise cross from wide on the left and Morrison aimed his magnificent header past Al Habsi from the edge of the six-yard box.
And the visitors almost increased their lead seven minutes later when Billy Jones cut in from the right and unleashed a fierce left-footed drive which flashed just wide of the busy Al Habsi's left-hand post.
That seemingly inevitable second goal duly arrived after 43 minutes when Jones' effort from a tight angle was deflected into his own net by Wigan captain Caldwell - but less than a minute later Kone pulled one back when he poked home Beausejour's cross.
Beausejour had the first chance of the second half when he hit a shot from the left side of the box high over Myhill's bar after the goalkeeper had parried from Watson, then Caldwell headed just wide as the home side enjoyed a significant spell of pressure.
The Baggies should have extended their lead in the 56th minute when Lukaku lashed a shot on the turn which was brilliantly tipped over the bar by Al Habsi at point-blank range.
Shaun Maloney should have done better for Wigan when he was teed up by a pass from Franco Di Santo in the middle of the box in the 72nd minute, but blazed his shot well over the bar.
Then a chance for Di Santo came to nothing in the 80th minute when he got his head on a Beausejour cross from the left but could only direct the ball against team-mate Kone, from whom it deflected onto the roof of the net.