Robin van Persie's deflected shot gave Arsenal victory over 10-man Birmingham.
Kenny Cunningham received a straight red card for scything down Fredrik Ljungberg just outside the area.
Soon after Maik Taylor guessed right to save a Robert Pires penalty, with the Birmingham goalkeeper going on to make a string of saves to frustrate Arsenal.
But with nine minutes remaining, Taylor was unable to stop Van Persie's shot which came off Stephen Clemence, a goal credited to the Birmingham midfielder.
The manner of the goal was a cruel ending for Taylor given how well he had played in the preceding 80 minutes.
His best two saves came early in the second half when he brilliantly tipped away a close-range shot from Ljungberg.
Taylor then stretched to get a fingertip on a Pires half-volley, a touch that was enough to push the ball on to the post.
Despite missing a host of players through suspension and injury Birmingham had adopted a positive approach before Cunningham's dismissal.
Blues wingers Jermaine Pennant and Julian Gray, both former Arsenal players, were keen to try and go past their markers at every opportunity.
Emile Heskey almost scored during that encouraging spell, his shot only partially stopped by Jens Lehmann, with the German keeper needing Ashley Cole to lash the ball clear.
Just past the hour, in a rare Birmingham counter-attack, Pennant released Heskey with an intelligent pass but the Birmingham striker fluffed his shot.
Birmingham's upbeat approach ensured Arsenal struggled to find any sort of tempo.
Ljungberg did manage to burst into the box but his run was brought to an abrupt end by Clemence's well-timed challenge.
That sense of timing in dealing with a Ljungberg run was conspicuously lacking from Cunningham and Johnson.
Cunningham's ill-conceived lunge on Ljungberg brought him a red card and soon afterwards Johnson conceded a penalty after fouling the Swede.
But setting the tone for the rest of the game, Taylor came to his side's rescue, first tipping over Reyes' free-kick following Cunningham's dismissal and then guessing right to save Pires' penalty.
Thereafter Taylor made at least half-a-dozen saves from Reyes shots, while Jamie Clapham and Olivier Tebily made important clearances for Birmingham.
Arsenal manager Arsene Wenger:
"Maik Taylor was superb - the only way we were going to score was through a goal like that," said Wenger, referring to Robin van Persie's deflected winner.
"It must be of the best goalkeeping performances I've seen at Highbury.
"The goal looked small when he was in it. He was calm and had a fantastic reach - you can give him 10 out of 10."
Birmingham manager Steve Bruce:
"Football can be cruel and we feel harshly done by.
"Maik has produced some great perfomances, but none better than that.
"He must have produced four or five world-class saves and was then beaten by a horrible deflection and bobble."
Arsenal: Lehmann, Lauren, Toure, Campbell, Cole, Hleb (Bergkamp 61), Fabregas, Silva, Pires (Van Persie 70), Ljungberg (Flamini 87), Reyes.
Subs Not Used: Cygan, Almunia.
Goals: Clemence 81 og.
Birmingham: Maik Taylor, Tebily, Cunningham, Upson, Clapham (Forssell 87), Pennant, Johnson, Clemence, Gray, Pandiani (Lazaridis 55), Heskey.
Subs Not Used: Vaesen, Painter, Aluko.
Sent off: Cunningham (24).
Ref: C Foy (Merseyside).