Birmingham City are leading Peterborough United at the break thanks to a 34th-minute strike from Nikola Zigic
The Midlands side had a bright start to the game and troubled Robert Olejnik early on as Zigic powered a header at goal from Paul Caddis's cross but the keeper made a good save.
The home side came close to taking the lead but were denied by a double save from Jack Butland, who first stopped a powerful Tommy Rowe shot and then blocked the follow-up from Lee Tomlin.
These saves turned out to be crucial as the visitors took the lead through Zigic as he tapped in from close range after Olejnik could only parry Chris Burke's powerful effort.
