Danny Ings struck his sixth and seventh goals of the season as Burnley maintained their unbeaten home record in the Sky Bet Championship this season.
The 21-year-old continued to help Clarets fans forget about their former prolific striker Charlie Austin - now at QPR - with a pair of neat finishes against Birmingham, the first after just three minutes.
Winger Scott Arfield headed home a second 17 seconds after the break and the in-form Ings made sure of the result with another goal eight minutes later.
The last notable action at Turf Moor had seen Ings hauled to the ground by last-man Lee Williamson in the dying embers of Saturday's 1-1 draw against neighbours Blackburn.
The offender judged it was better to take the 'professional' dismissal than let Ings through one-on-one. And, as if to vindicate Williamson's choice, the striker converted his first chance.
Strike-partner Sam Vokes came away from his marker and hooked the ball through for Ings, who steadied himself and coolly lifted his shot in to the corner.
The space he was afforded by Blues' defence was alarming and he was left alone again moments later, this time side-footing wide from Arfield's cross.
However, the hosts' back four was equally poor in failing to tackle the fleet-footed Chris Burke, whose cross-cum-shot narrowly evaded Lee Novak in front of goal.
Birmingham continued to leave the door open, though, an unmarked Ings heading over Michael Kightly's delivery while Kyle Bartley's misplaced pass sparked a move which culminated in Vokes lashing wide.
Bartley tried to make amends at the other end only to head off target when meeting a near-post corner on the stroke of the interval.
The Clarets opened the second half in the same manner they began the first as Arfield doubled their advantage.
Vokes and Ings were both involved before Kightly curled a cross to his fellow winger to head back across goal and in to the net.
The relief was noticeable for Arfield as it was his error that led to Jordan Rhodes' equaliser in the derby, a result which preserved Blackburn's 34-year unbeaten record against their fierce rivals.
Darren Ambrose then headed over at the other end but the hosts were rampant and Ings struck again after 54 minutes.
Arfield drifted inside and flicked the ball into the striker's path, allowing him to race away before confidently clipping the ball past Blues goalkeeper Darren Randolph.
The stopper could have been picking the ball out of his net again, Vokes twice going close and Ings blazing over when presented with his hat-trick chance.
Former Burnley midfielder Wade Elliott drove wide for Lee Clark's side, but it was a night to forget for a team now without a league win in five games.