A late Britt Assombolonga goal gave Middlesbrough all three points, despite a Che Adams leveller.
A much improved second half saw Blues rewarded with a goal, but moments later substitute Assombolonga nicked all the points for the play-off contenders.
Tony Pulls fielded a defence orientated team, with four defenders and five midfielders. The opening passages of play were made difficult for Blues who were up against a team that defended as a whole unit. The discipline in their defending was evident from the limited chances created, with Jotas free kick the best chance for the home side early on. The Spaniards free kick was struck well but had too much height to trouble former Blues keeper Darren Randolph.
Middlesborough almost went in front with two chances around the six-yard box. The first shot by Jordan Higull blocked by Maikel Kieftenbeld and the follow up quickly blocked again by Kieftenbeld.
The away side didn’t have to wait much longer though as minutes later Lewis Wing put them in front as the half drew to an end. Dael Frys low cross was slid in by Lewis Wing who finished from close range into an open net.
Blues did create more for themselves after the interval and pressed deeper into the Boro half. Jota’s left footed free kick was delivered well to the far post where Dean was waiting. The defender made connection but no accuracy and saw his close ranger header hit the post.
The game shifted into a pattern of Birmingham chances. Another free kick almost worked for Blues. This time Lukas Jutkiewicz, from the same place he scored during the 3-0 win over Rotherham, stepped up. Jota layed off the ball for his team mate whose powered shot darted through the Boro defenders and was met by an alert Darren Randolph in goal, who did well to catch the effort.
A deserved equaliser did arrive for the home side with just over ten minutes to go. Jota again being involved in the chance. His chipped ball to Jutkiewicz set up Adams who spun his defender to create a shooting opportunity. On the turn, Adams fired right footed far into Randolphs left side of the goal with the sheer accuracy giving him no chance of saving.
Fittingly, Isaac Vassal then entered the pitch in place of Maikel Kieftenbeld to a raucous reception. However, the mood was short-lived as Blues fell behind just three minutes after their equaliser.
Lewis Wing flicked on a ball to Assombolonga who got between the last two Blues defenders and away on goal. The substitute cooly chipped an effort over Lee Camp in goal to restore their lead. It was the classic counter-attack goal from the visitors, who had been absent in their attack in the second half.