Matt Derbyshire's first goal in England in nearly two years proved vital as Birmingham squeezed through into the Carling Cup third round with a 3-2 win over Rochdale.
Derbyshire last found the net for Blackburn in the quarter-finals of this competition in December 2008 before joining Olympiacos from Ewood Park.
He returned to England last week and popped up with a poacher's effort to guide Alex McLeish's side to an unconvincing win over their npower League One opponents.
Dale skipper Gary Jones twice found the target in front of a crowd of just 6,431 but goals from Derbyshire, James McFadden and David Murphy proved enough for the Barclays Premier League side.
Jones gave Dale a shock lead, before McFadden leveled from the spot after Marcus Holness brought Derbyshire down.
Goals from Murphy and Derbyshire then looked to have made Birmingham safe, before Jones' second brace of the season made for a tense finish.