A stunning 20-yard strike by James Morrison helped West Bromwich beat local rivals Birmingham to ease their Premier League relegation fears.
After a quiet first half, Youssouf Mulumbu sparked the match into life when he poked in from close range.
Just over a minute later, Jean Beausejour equalised for the Blues when he turned in Lee Bowyer's low cross.
Morrison's left-foot drive restored the Baggies lead at St Andrews before Paul Scharner headed in the third.
It was a deserved scoreline for Roy Hodgson's team. They looked far more spritely than Birmingham, who appeared sluggish a week after their epic Carling Cup final win.
Win could be crucial - Hodgson
However, neither team will look back at the first half with any great fondness.
The only occasions on which a goalmouth was threatened came from two efforts by Birmingham's Cameron Jerome.
His first was a weak shot from 20 yards that trickled past Scott Carson's left-hand upright, the former Cardiff forward then directing a stooping header wide of the same post.
But the yawn-inducing first half was soon a distant memory two minutes into the second, when Mulumbu bravely slotted in from 12 yards.
Substitute Peter Odemwingie, brought on after the restart, fed Congolese midfielder Mulumbu who took a knock en route to beating Ben Foster with his shot.
But the cheers of the visiting fans were short-lived - 79 seconds, to be precise.
It was a simple Blues move that led to the equaliser. Full-back Stephen Carr found Bowyer and the former Newcastle midfielder delivered a precise square ball into the six-yard area for Beausejour to turn in.
If that goal was admirable for its simplicity then West Bromwich's second was admirable for its audacity.
Blues defending angers McLeish
Midfielder Morrison, returning to the starting XI, collected a pass from Steven Reid before pushing the ball a foot past Curtis Davies and letting fly.
It was sensational strike, similar in brilliance to the one he scored against Manchester United earlier this season.
Odemwingie then blazed over from eight yards after Chris Brunt's shot smacked Foster's left-hand post and landed in the Nigerian's path.
But the visitors' third finally came when the dogged Scharner popped up at the far post to head in Morrison's cross from what seemed an impossible angle to wrap up a vital win.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.