Middlesbrough and Birmingham City have been unable to produce a goal in the first 45 minutes at the Riverside Stadium.
The visitors were forced into a change after just four minutes as Keith Fahey replaced the injured Jonathan Spector.
Nikola Zigic twice put Wes Thomas through on goal, but he was unable to breach the deadlock.
Boro had the ball in the net 10 minutes before half time, but Scott McDonald was ruled offside after following in George Friend's saved shot.
Jonathan Woodgate then made a crucial tackle at the other end to once again prevent Thomas from opening the scoring.
Jason Steele beat away a Ravel Morrison shot in the dying moments of the first half.