Birmingham crushed their city rivals in a fiercely competitive and eventful derby at St Andrews.

Villa's embarrassment was compounded by a horrendous mistake from goalkeeper Peter Enckelman that gifted the Blues their second goal.

The visitors, who fell behind to a first-half strike from Clinton Morrison, had looked in contention until Enckelman miskicked a throw-in from Olof Mellberg, allowing it to roll into his unguarded net.

Referee David Elleray ruled that the Finn had made faint contact with the ball and signalled a goal.

Villa gave a starkly different performance in each half.

They were awful during the first 45 minutes as Birmingham, with Robbie Savage and Aliou Cisse superb in the centre of midfield, dominated.

Villa boss Graham Taylor started with Mark Kinsella the only recognised midfielder included in his 3-5-2 formation.

And the visitors struggled to keep possession, allowing their hosts a succession of chances.

Cisse and Geoff Kenna both had good chances before Morrison put the Blues ahead in the 31st minute.

Mellberg failed to clear a punt into his box and Morrison stretched forward to slot home from seven yards.

Birmingham continued to dominate for the rest of the half and it was no suprise when Taylor made changes at half-time.

Yet it seemed hard on strikers Marcus Allback and Juan Pablo Angel, who endured a paucity of service, to be replaced by Darius Vassell and Dion Dublin.

Saying that, Villa were vastly improved during a second half in which they looked the more likely side to score.

Taylor was livid when Vassell was ruled offside before netting in the 57th minute.

And the former England manager was both angry and bemused when Birmingham extended their lead in the most bizarre of circumstances.

Mellberg took a throw-in from the left touchline and Enckelman shaped up for a routine clearance.

But he missed the ball with his kick, allowing it to roll under his foot and into the net.

The visitors still looked in shock when Horsfield, on for goalscorer Morrison, stole the ball from Alpay near the edge of his own box and drove forward before shooting low past Enckelman.

Birmingham: Vaesen, Kenna, Purse, Cunningham, Grainger, Devlin (Powell 79), Savage (Hughes 87), Cisse, Damien Johnson, John, Morrison (Horsfield 69).

Subs Not Used: Bennett, Lazaridis.

Booked: Grainger, Purse, Cisse.

Goals: Morrison 31, Enckelman 77 og, Horsfield 83.

Aston Villa: Enckelman, Mellberg, Alpay, Staunton, De la Cruz, Kinsella, Johnsen, Barry, Samuel, Allback (Dublin 45), Angel (Vassell 45).

Subs Not Used: Postma, Hendrie, Moore.

Booked: Alpay, Barry.

Attendance: 29,505.

Referee: D Elleray (Middlesex).