Curtis Davies' unfortunate own goal gave Blackpool a slender 1-0 advantage over Birmingham in the first leg of their npower Championship play-off semi-final.
Gary Taylor-Fletcher prodded home from an offside position for the hosts, while Davies headed off target at the other end in a frenetic opening.
Marlon King might have done better when his shot from Chris Burke's cutback clipped the top of the bar at the end of a clinical 40th-minute counter attack.
The hosts broke the deadlock 44 minutes into an evenly-matched first half when Tom Ince's speculative low drive took a significant deflection off Blues captain Davies.
Ian Holloway introduced Nouha Dicko and and Kevin Phillips in a straight swap for forwards Stephen Dobbie and Taylor-Fletcher and the latter thought he had made an instant impact against his former club, only to be flagged offside after heading home a right-wing cross from namesake Matt.
King was agonisingly close to levelling the tie in the first minute of stoppage time, stretching to steer Wade Elliott's knockdown against the woodwork.