Boro fell behind to Maxime Colin’s opener but took the lead after first-half goals from Britt Assombalonga and George Saville. Lewis Wing then scored twice in the second half to complete the scoring.
Our Middlesbrough writer Joe Nicholson has dished out his marks from the match – scroll down and flick through the pages of our picture gallery to see them:
9. Lewis Wing - 7
Quiet in the first half but grew in confidence. The midfielder’s corner put Boro 3-1 up before a powerful striker made it four. 7 Photo: Alex Burstow
10. Marvin Johnson - 8
Another assist for the Boro winger after a low cross for Saville’s goal. Put pressure on the Birmingham defence in the first half. 8 Photo: George Wood
11. Britt Assombalonga - 8
Justified his selection with a strong performance up front. Held the ball up and produced an assured finish to draw Boro level. 8 Photo: Getty Images
12. Djed Spence - 6
Djed Spence (for Johnson, 72) Provided fresh legs on the flank. 6 Photo: Clive Brunskill