Championship side Birmingham City are leading Swansea City 1-0 in their FA Cup fourth-round tie, thanks to Lee Novak's goal.
Albert Rusnak came close for the hosts in the opening stages, but after cutting inside, he saw his strike deflect wide of the post.
The hosts took the lead on 15 minutes when Novak met a cross from Paul Caddis and flicked the ball past the keeper.
Rusnak came close to adding a second soon after, but saw his strike cleared off the line by Ashley Williams.
Birmingham continued to create chances, with Chris Burke and Reece Brown firing efforts wide, as they finished the first half in the lead against their Premier League opponents.
