New Birmingham City boss Steve Cotterill made a winning start as his much-changed side beat Championship leaders Cardiff City.
Che Adams provided the only goal of the game on 19 minutes with a low, right-foot shot after a superb mazy run.
Neil Warnock’s off-colour Cardiff failed to register a shot on target against their fired-up hosts.
And Blues could have won by more, with Adams and Jacques Maghoma both denied in one second-half scramble.
Cotterill’s side, beaten 6-1 at Hull in their previous game, climb three places to 19th, while Cardiff will be overtaken at the top if Wolves avoid defeat at home to Aston Villa on Saturday.
Adams looked lively from the opening stages and could even have earned an early penalty when he was held back by Sean Morrison as he attempted to run into the box.
His moment of inspiration came midway through the first half, straight from Cardiff keeper Neil Etheridge’s clearance.
Picking up the ball wide on the left close to the halfway line, he opted to take on the visiting defence single-handed.
He put his head down and ran, slicing his way past four men in red before cutting inside to drill a low, curled right-foot shot which nutmegged Morrison before finding the right corner.
Cardiff, although not at their best as they suffered only their second defeat of the season, did carry some threat, surpassing their hosts on the corner count as they lay siege late on.
Junior Hoilett also shot just wide in the first half, while a tremendous far-post clearance by home skipper Michael Morrison after the break was a key moment too.
But they also had to survive a double let-off when Adams’ shot was blocked before Bruno Manga cleared off the line from Maghoma.
It took a brave clearance by Cardiff captain Morrison to thwart Isaac Vassell when he looked set to head home the second goal Cotterill’s side perhaps deserved.
Birmingham City manager Steve Cotterill told BBC Sport:
“I’m very proud of the players for all they’ve done for me over the past couple of weeks. But what I’ve seen’s no different to what I saw when I was here at the end of last season.
“We’ve just worked really hard at all aspects of our game and what we expected Cardiff to throw at us. And we stood up to be counted.
“It was a great goal by Che Adams. And we might have deserved another one too.”
Cardiff City manager Neil Warnock told BBC Sport Wales:
“I am disappointed; I thought we started ever so sluggishly.
“You expected Birmingham to come out of the traps with a new manager and I thought they did well for half an hour. But I thought we came into it and second half if we had been like ourselves I thought we could go on and win it.
“We were a lot better in the second half so I can’t complain, but we didn’t have enough shots. But it was always going to be tight. It was one of those nights.”