But with the visitors committed to attack, gaps started to appear at the back, with DJCampbell twice getting himself into good positions only to squander the chances.
Marlon Harewood and DJCampbell both scored to cancel out goals from Stewart Downing and Nathan Delfouneso but Villa defender James Collins headed a late winner to deny the Seasiders at the death.
Matthew Upson missed a great chance when his header hit the post but Birmingham were unable to battle back, despite the introduction of former Brentford FA Cup hero DJCampbell as a substitute.