Scott Hogan struck the winner in the second half after the home side played for the majority of the second period with 10 men following Liam Shaw's red card.

Shaw was shown a second yellow card after fouling Maxime Colin five minutes after the restart and the Owls paid the price.

The goal came after 63 minutes when Hogan got on the end of a low driven cross by Bela to guide the ball past Keiren Westwood.

Birmingham moved out of the bottom three with the three points and plunged managerless Wednesday down to 23rd in the Sky Bet Championship.

Karanka said: "The main thing was to win today. With this togetherness, you have to keep the trust in these players because they have more than enough to stay up.

"Words can't explain how important this game was at the beginning. It was difficult to play because there was a lot of pressure on this game.

"We managed the game really well, especially when you are playing against 10 men.

"We were controlling the game before the sending off and when they got the sending off, it was easier.

"The players were really good. They were really consistent and really together. I think it is a good turning point.

"I think the team is very good. I don't have any doubt that we have more than enough. We were much better than our last four or five opponents, but the difference is that we won today."

Sheffield Wednesday caretaker manager Neil Thompson rued a sluggish start from his side.

He said: "I think in the first half we were a bit lethargic. We didn't get on the ball enough and weren't brave enough to get on it.

"I think it took the sending off for us to show more urgency with the ball. We created one or two chances.

"We changed our system two or three times and I thought we put them on the back foot a little bit in the second half.

"This week has been a disappointing week after the 1-0 defeat at Stoke as well but we've still got a lot of games left so we've got to dust ourselves down and go for the next game.

"I thought we controlled large parts of the first half without being really effective and in the second half we've had a bit of a go, I thought, but it was too little, too late.

"You've got to show character and you've got have the stomach for the fight.

On Shaw's sending off, Thompson said: "You can't leave the ground and the lad is devastated."