Jonathan Grounds and Craig Gardner kept Birmingham's Championship survival hopes alive with crucial goals in a 2-0 win over Nahki Wells and his Huddersfield teammates at St Andrew's.
Wells started the match on the bench, before entering the game at the start of the second half.
A beaming Birmingham caretaker manager Harry Redknapp was delighted with the result which was achieved by a tremendous team effort.
Second-half goals from Reggie Lambe’s teammates Jabo Ibehre and Nicky Adams fired Carlisle back into the Sky Bet League Two play-off picture as a 2-1 win over Newport County and left the Welshmen facing an agonising last day battle to preserve their league status.
County grabbed an early lead through defender Micky Demetriou, but relentless Carlisle pressure finally paid off with two goals in two minutes.