Source: Team_Talk
Gabby strikes late to break Blues
Agbonlahor struck with six minutes remaining to earn Martin O'Neill's side a third straight win, a fifth in a row against their fierce rivals, and sixth place in the Premier League.
Birmingham had actually dominated much of the second period but they failed to seriously trouble Brad Friedel and were made to pay when Agbonlahor capitalised on slack marking to head in.
Villa, with three debutants in defence, James Collins, Richard Dunne and Steven Warnock, had started the stronger of the sides in the midday kick-off and coped easily with Birmingham's initial advances into their half.
They had the first real chance to get on the scoresheet in the seventh minute when Agbonlahor slipped the ball to James Milner inside the penalty area but the midfielder wanted too much time and his right-foot shot was well wide of Joe Hart's right-hand upright.
The visitors were then forced into some desperate defending as shots from Gary O'Connor and Sebastien Larsson were prevented from reaching their target.
Milner then squandered another chance to put Villa in front in the 21st minute when he met Agbonlahor's low cross with a first-time effort that scuffed off his boot and out of play.
Both sides struggled to gain control in the midfield but the home side, boosted by the speed of James McFadden on the left and the work-rate of Larsson on the right, finally created their first real opening on the half-hour when a neat flick-on by O'Connor put Lee Bowyer in the clear.
The City midfielder tested Friedel with a stinging right-foot drive that the American keeper did will to punch to safety and moments later a long range effort from Keith Fahey flashed just wide of the post.
But Villa continued to look the more likely to score and within seconds Milner sent a 20-yard drive wide of the target at the opposite end.
He missed yet another chance in the 40th minute, being picked out by Ashley Young at the far post but failing to get his shot on target despite being left completely unmarked.
Agbonlahor then headed a Young cross wide of the target before half-time and City responded by replacing James McFadden with Lee Carsley at the start of the second-half.
In the 51st minute, Steve Sidwell was booked for bringing down Larsson in full flight, while Carsley tested Friedel with a curling shot from the edge of the penalty area soon after that the former Blackburn man was equal to.
Another shot from Carsley failed to trouble Friedel but it was a similar story at the opposite end with City's defence holding firm against Villa's sporadic forays into their half.
Agbonlahor sprinted towards the City rearguard in the 64th minute but he soon found himself in a blind alley as he ran out of steam and ideas.
Moments later the Villa striker found himself in the referee's notebook for a foul on Franck Queudrue. Agbonlahor could have no complaints as he clearly shoved the City defender to the ground as he raced on to the ball.
The game was crying out for some quality on the ball but it was not supplied by Bowyer, the City midfielder trying his luck from 25-yards out but sending his effort well wide of the target.
But Villa were living dangerously. Collins twice failed to clear his lines and then Milner was forced to foul Fahey as City applied more pressure, with Larsson's resultant free-kick failing to find the target.
The visitors finally began to find their feet again, though, and created a chance in the 77th minute when Sidwell headed at Hart following a cross from Warnock.
Hart had to dive low to his left to keep out a 20-yard Milner effort three minutes later but he could do nothing in the 84th minute when Young's free-kick was nodded back by substitute John Carew for Agbonlahor to apply the necessary finish from close range.
