Graham Dorrans's late free-kick earned West Brom their first league win of 2012 as they edged past Stoke City.
James Morrison gave Albion the lead when his swerving effort from the edge of the area caught out Stoke goalkeeper Thomas Sorensen.
Ben Foster saved a second-half penalty from Jonathan Walters before substitute Cameron Jerome headed an equaliser.
Just as Stoke looked to have earned a point, Dorrans hit a free-kick through a crowd of players into the net.
Stoke came into the game with just one win in five league outings, but only a solitary defeat in nine.
Did you know?
The last time West Brom beat Stoke was in September 2003 when they met in the second tier with the Baggies winning 1-0 at the Hawthorns.
That ensured they were clear favourites against a West Brom side who had not beaten them in 10 games.
The Baggies' form coming into the game was hardly inspiring either, with three league defeats on the trot instigating a slide down the table from their comfortable mid-table position at Christmas.
Roy Hodgson's side got off to a bright start. Morrison's long ball forward got caught up in the wind at a blustery Britannia Stadium to allow Jerome Thomas to get in behind the Stoke defence, but his shot was saved by Sorensen.
The Dane then pulled off a sensational save after Morrison hit a rasping strike that the keeper managed to tip on to the underside of the bar.
'Flat' Stoke display disappoints Pulis
However, a mistake marred the Stoke keeper's solid performance as Morrison opened the scoring.
The midfielder hit a low strike that swerved just in front of Sorensen, who failed to adjust in time and could only get a hand to the ball before it crept over the line.
The woodwork again denied Morrison after the restart when the midfielder controlled the ball on the edge of the area and fired past Sorensen, only for it to bounce off the upright.
Stoke then won a penalty in controversial fashion when Gareth McAuley brought down Walters in the box.
Despite protests from the Albion players, referee Anthony Taylor pointed to the spot. However, Ben Foster stooped down to save Republic of Ireland international Walters's powerful spot-kick.
Stoke boss Tony Pulis brought off Ryan Shotton and replaced him with Cameron Jerome - and the striker met fellow substitute Jermaine Pennant's free-kick to bring the game level with four minutes to go.
Did you know?
Cameron Jerome's two Premier League goals for Stoke this season have both come when he has been introduced as a substitute.
That looked to have been it but, in injury time, Dorrans stepped up to take a free-kick out wide on the left. His effort somehow found its way through a crowd of players before nestling in the bottom corner to earn West Brom a deserved victory.
Stoke manager Tony Pulis:
"I am disappointed. That is probably as flat as we have been in a long time. I have not seen the two goals yet but they looked like ones we do not normally concede.
"What we have achieved over the past couple of months means we have set high standards, but we have not lived up to those in this game.
"The second goal was a disappointing goal to concede but it was not our day. We have got a big game against Derby next week, you have to knuckle down and bounce back."
Hodgson hails 'significant victory'
West Brom manager Roy Hodgson:
"It was a significant victory. It was terrific to come back today after last week's defeat against Norwich and get three points.
"We had a few chances in the second half, but when they get a late equaliser it becomes a worry that they might go on to win it with the home fans behind them.
"The better chances were ours so I think we can say we deserve it."
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