Boro draw a blank against battling Blues
Birmingham ended their three-match losing streak in the Sky Bet Championship with a battling draw at promotion-chasing Middlesbrough.
Gary Rowett's side frustrated second-placed Boro to claim their first point in over a month, denying the Teessiders their fourth consecutive league win.
Aitor Karanka's men managed to keep hold of their automatic promotion spot, but David Nugent was sent off late on to round off a disappointing afternoon.
Boro started brightly and almost took the lead in the second minute when Emilio Nsue burst forward down the right before laying off for Adam Clayton, whose delicate chip was turned round the post by Blues goalkeeper Tomasz Kuszczak.
The home side had another good chance four minutes later when Albert Adomah broke down the left and clipped a good ball into the box, but Stewart Downing's poor header was well wide.
City pushed forward shortly after and after Boro failed to clear a cross, the ball fell to Stephen Gleeson whose drilled shot skidded just wide of Dimi Konstantopoulos' right-hand post.
Boro began to dominate as they searched for the opener, and skipper Grant Leadbitter almost found it in the 13th minute but his deflected shot hit the post.
Birmingham came out after the break with more intent and pegged Boro back into their own half.
They should have nudged in front five minutes into the second half when Boro failed to clear in the box and the ball dropped for Michael Morrison, but his shot was deflected wide by Ben Gibson's lunging leg.
Boro went close again in the 58th minute when Downing carried the ball 20 yards and laid off for Adomah who crossed to the far post for Cristhian Stuani, but the Uruguayan's sliding effort hit the side netting.
Stuani was guilty of wasting another glorious chance in the 66th minute when Nugent dummied Adomah's ball into the box but the forward's first-time effort looped high over the bar.
A minute later Downing's powerful shot was bravely blocked by Morrison as Boro started to pressure again.
The game started to open up as both sides looked for the first goal and Konstantopoulos did well to tip Jacques Maghoma's strong shot over the bar before Demarai Gray saw a curling effort sail just past the post.
Stuani missed another good chance with 15 minutes to go when his disappointing header from substitute Adam Forshaw's cross landed safely into Kuszczak's hands.
City should have taken the lead in the 80th minute but Konstantopoulos did well to block Gray's close-range effort and Morrison headed Gleeson's corner inches wide in the last minute.
Nugent saw red in stoppage time after clashing with Gleeson to retrieve a dead ball which only compounded Boro's frustrations.