Birmingham overcame a second-half fightback from Burnley to steal a march on their Championship play-off rivals.
Ross Wallace was utilised as an emergency left-back for Burnley in the absence of injured duo Ben Mee and Danny Lafferty, while Charlie Austin’s hat-trick from the bench in Saturday’s 5-1 victory at Portsmouth earned him a start in attack alongside Josh McQuoid.
Marlon King fired his 16th goal of the season to give the Blues an early lead.
The home side were sparked into life by the introduction of Junior Stanislas before the hour and forward duo Danny Ings and Austin both hit the crossbar before the former levelled for the Clarets.
The visitors responded instantly and Jordon Mutch netted his first goal for the club with 15 minutes to play, leaving full-back David Murphy to apply gloss to the scoreline when Burnley goalkeeper Lee Grant dropped Mutch’s cross.
Ings blazed over when given the opportunity to set up an exciting finish.
Birmingham are now three points clear of seventh-placed Middlesbrough, who are outside the top six on goal difference, having won their game in hand on the clutch of teams on 63 points.
At the turn of the year Eddie Howe’s Clarets also harboured play-off ambitions, but they remain 16th and on a run of only four wins in 16 matches.