Goals from substitutes Koji Miyoshi and Lukas Jutkiewicz gave Birmingham a 2-0 Championship away win against a Bristol City side who finished with 10 men.
The visitors took the lead in first-half stoppage time when Keshi Anderson’s corner was not cleared and Miyoshi, just introduced for the injured Ethan Laird, found the roof of the net with a sweet right-footed volley.
The home side’s task became more difficult when centre-back Rob Dickie was shown a second yellow card on 75 minutes for blocking a run by substitute Jordan James, having already been booked for dissent in the first half.
And any hope the home side had of a recovery was snuffed out six minutes from time when Jutkiewicz, introduced on 73 minutes as a replacement for Anderson, converted a low right-wing cross from close range.
Birmingham were good value for a win that maintained their promising start to the season, while inflicting a first defeat on their hosts.
Robins boss Nigel Pearson gave a first start of the season to winger Anis Mehmeti, while Birmingham were unchanged from their 1-0 home victory over Leeds.
Blues made a bright start and their first attack saw Scott Hogan head over from Juninho Bacuna’s left-wing cross.
Defences dominated for much of the first half and chances were at a premium. Siriki Dembele fired over from distance for Birmingham on 21 minutes.
Four minutes later the hosts’ first meaningful goal attempt saw Sam Bell’s shot blocked. Dickie headed over from the resulting corner.
Birmingham looked more dangerous and Max O’Leary had to save a Bacuna shot on 35 minutes. Then came the injury to Laird that saw Miyoshi sent on as a 40th-minute replacement.
The Japanese substitute made an immediate impact, forcing a good save from O’Leary before breaking the deadlock deep into three minutes of injury time.
Both managers made changes at the break, Pearson sending on Haydon Roberts and Mark Sykes for Cameron Pring and Harry Cornick while Blues boss John Eustace introduced James for Dembele.
Bristol City began the second half on the front foot, Zak Vyner failing to make contact with a Mehmeti corner and a Sykes run halted by a foul that earned Lee Buchanan a booking.
But Birmingham soon responded and Bacuna grazed a post with a left-footed shot before Miyoshi sent another effort wide.
Both sides were fully committed but still it was Blues creating more openings as a James shot brought a diving O’Leary save.
Dickie’s dismissal only seemed to fire up the home side and substitute Nahki Wells should have equalised on 82 minutes when shooting wide from Bell’s low cross.
It proved an expensive miss as Jutkiewicz quickly settled the outcome.
