Birmingham City 1 Aston Villa 2: This fixture has heaped embarrassment on Aston Villa goalkeepers in recent seasons but yesterday it was Liam Ridgewell's turn to experience the torment.

Having swapped Villa Park for St Andrew's in the summer, the Birmingham captain endured an afternoon that will cause him to wake up in cold sweats for weeks to come as he recalls the nightmare memory of an early own goal and his part in Gabriel Agbonlahor's late winner.

Steve Bruce's side looked the more likely to emerge with three points when Mikael Forssell headed a splendid equaliser with 28 minutes remaining. Emboldened by Forssell's goal, the home team poured forward in search of a second only to be undone when Agbonlahor outjumped Ridgewell in the 87th minute. It was another personal victory for Agbonlahor after the forward had cleared his former team-mate's header off the line at the opposite end two minutes earlier.

"That just shows what a fine line it is," reflected Bruce. Birmingham's manager was crestfallen. He believed his side should have been awarded two penalties before the interval after Zat Knight handled and then Daniel De Ridder tumbled in the area following Martin Laursen's careless challenge.

The first claim appeared doubtful but Bruce was entitled to feel aggrieved when the referee, Steve Bennett, waved away De Ridder's appeals and booked the Dutchman for diving.

Birmingham's sense of injustice deepened when Agbonlahor struck to earn Villa their first away win in the league this season.

The visitors had been the better side before the interval but the introduction of Forssell at half-time gave Cameron Jerome the support he craved in attack. Until that point Villa had been able to suffocate Birmingham's threat, the visitors comfortable after Ridgewell's faux pas had subdued the home din.

There had appeared little danger when Stilian Petrov wriggled clear and delivered a low cross into the six-yard box in the 10th minute but Ridgewell was slow to react, the ball striking his left thigh and ricocheting beyond Maik Taylor.

Bruce admitted Birmingham had been "stunned" by the goal, and it took the interval to refocus minds.

Bruce sacrificed the midfielder Wilson Palacios at half-time for Forssell, the Finn's arrival proving the catalyst for a sustained assault on the Villa goal that brought reward in the 62nd minute. Olivier Kapo and Fabrice Muamba neatly combined to release De Ridder on the right, whose wonderful cross picked out Forssell, who thumped a powerful header past Scott Carson for his second of the season.

The goal galvanised Birmingham and unnerved Villa and as the game became stretched there was an ebb and flow that promised late drama. Ridgewell thought he had found redemption when he climbed imperiously to head Sebastian Larsson's cross towards the far corner but Agbonlahor stuck out a boot.

The striker's contribution was every bit as telling 120 seconds later when he sneaked ahead of his marker to glance Young's cross inside the far post. "You couldn't have written a script like that," admitted Ridgewell.

• Guardian Service