The game, which took a long time to come to life, finished on a high note with two goals in the last ten minutes when Sunderland were down to ten men after Carlos Edwards had limped off injured.
Paul McShane had given Birmingham a first-half lead with an unfortunate own goal, but Michael Chopra - Sunderland's £5million summer signing from Cardiff - scored a solo equaliser in the 75th minute.
Garry O'Connor became an immediate hit with Birmingham City's fans when he scored his first goal on his Premier League debut.
The £2.5million summer signing from Lokomotiv Moscow notched the vital 82nd minute goal and Birmingham appeared to be heading for a home win until John popped up with his equaliser after Colin Doyle had made a brilliant save.
O'Connor proved himself to be an astute marksman when he collected a Mikael Forssell pass and coolly slotted a left-foot shot past Craig Gordon.
His goal came seven minutes after Chopra had grabbed a 75th minute equaliser for the Black Cats to demonstrate his goalscoring prowess to notch his second goal in two games.
It was not until the 28th minute that the stalemate was broken.
A high looping free-kick from Seb Larsson was seemingly well covered by the Sunderland defence but it found Stephen Kelly on the edge of the six yard box.
His header back across goal hit the unfortunate McShane on the chest and was deflected into the net at the far post.
Sunderland were unable to make much impression as an attacking unit at this stage.
Chopra was generally kept subdued by Liam Ridgewell and Johan Djourou until the former Cardiff striker struck in devastating fashion.
Previously Sunderland's main threat came from the speedy Edwards, who scored a spectacular goal on his last visit to St Andrew's.
Birmingham's new-look team, however, impressed the home fans with their energetic approach until Sunderland's late pressure put the game into the melting pot.
Olivier Kapo made a quiet start, but the Frenchman later created a good impression with some clever play as he outwitted several Sunderland defenders.
But the Black Cats could never be underestimated. Despite his own goal, McShane gave a typical all-action performance which obviously fits into manager Roy Keane's Premier League survival plans.
The £2.5million summer signing from West Bromwich Albion was particularly outstanding in the second half when Forssell was shut out of the game.
Forssell was eventually joined attack by the Scotland international striker O'Connor, who took over from Gary McSheffrey in the 65th minute.
It proved to be a master move as he produced the crucial 75th goal after Sunderland had forced themselves back into the game.
A header from Dickson Etuhu was missed by Ridgewell and Chopra raced onto the loose ball to hammer a powerful left footed shot past Doyle in the 75th minute.
O'Connor then converted a Forssell pass but John, who had earlier hit the woodwork, could not be denied and he grabbed a last-gasp equaliser.