Birmingham earned a well-deserved point against a subdued Manchester United.
Steve Bruce's side had chances to win, with United goalkeeper Roy Carroll denying Emile Heskey with his legs either side of the interval.
United, with Wayne Rooney on the bench, rarely troubled Birmingham, but Ruud van Nistelrooy missed the game's best opportunity after 36 minutes.
He side-footed straight at goalkeeper Maik Taylor from only six yards as he raced on to Quinton Fortune's cross.
United rested Rooney, pairing Van Nistelrooy and Alan Smith up front.
And Birmingham had an early escape when Taylor clearly picked up Mario Melchiot's back-pass on his goal-line, but referee Mark Halsey mysteriously ignored United's claims.
Birmingham's dogged approach unsettled United, and goalkeeper Carroll was forced to block Heskey's shot after Kleberson conceded possession.
Van Nistelrooy had the best opportunity of the first period in the 36th minute, when Quinton Fortune's perfect cross found the Dutch striker inside the six-yard box.
A goal looked certain, but Van Nistelrooy's side-footed effort was saved by Taylor.
Birmingham made a change during the interval, sending on veteran Darren Anderton for his league debut for the club, replacing the disappointing Jesper Gronkjaer.
United were making little headway, and inevitably Ferguson introduced Rooney for Kleberson after 58 minutes.
But Birmingham almost marked his arrival by going ahead, Carroll once more denying Heskey with his legs after a fine ball from Robbie Savage.
And Rooney needed treatment when he appeared to sustain a dead leg in a challenge with Savage, but he was able to resume.
Ferguson was desperate to break the deadlock, and sent on Paul Scholes for Cristiano Ronaldo with 14 minutes left.
United were having trouble penetrating the Birmingham defence, but Van Nistelrooy was narrowly off target with a first-time effort with time running out.
Smith flashed a 25-yard drive inches wide, but United had to settle for a point.
Birmingham: Maik Taylor, Melchiot, Cunningham, Upson, Gray,
Johnson (Tebily 90), Dunn, Savage, Gronkjaer (Anderton 45),
Heskey, Yorke (Clapham 90).
Subs Not Used: Bennett, Martin Taylor.
Man Utd: Carroll, Gary Neville, Ferdinand, Brown, Fortune,
Smith, Kleberson (Rooney 59), Keane, Ronaldo (Scholes 77),
Saha, van Nistelrooy.
Subs Not Used: Phil Neville, O'Shea, Ricardo.
Ref: M Halsey (Lancashire).