Neil Warnock’s side had won three successive matches against Peterborough United, Barnsley and Cardiff City but failed to make it four as they hosted the Blues.
The loss leaves them in 11th place – still only three points from the top six, however they are also the same distance away from 19th.
The defeat means eight of Middlesbrough’s last 10 fixtures have ended with a 2-0 scoreline – unfortunately not all in their favour.
The Championship club are back on the road tomorrow evening as they travel south to take on Luton Town, who currently sit on the same points as Boro.
Here are the best of today's Championship rumours...
5. Everton set for battle over signing of Nottingham Forest youngster
Everton are joining Crystal Palace and a few other Premier League clubs in the race to sign Nottingham Forest's Brennan Johnson. The 20-year-old has three goals and three asissts in the Championship this season. (Football League World) Photo: George Wood
6. Derby County goalkeeper available for January move
Derby County have reportedly made keeper David Marshall available for a January move, despite spending most of last season as their first choice. The 36-year-old has slipped down the pecking order behind Kelle Roos and Ryan Allsop. (Derby Telegraph) Photo: Alex Pantling
7. Middlesbrough lining up move for Aberdeen winger
Middlesbrough are set to revisit their interest in Aberdeen winger Ryan Hedges in January. Blackburn Rovers are also keen on the 26-year-old. (Football League World) Photo: Ian MacNicol
8. Released Huddersfield Town striker training with non-league side
Ex-Huddersfield Town forward Oumar Niasse has ben training with non-league side West Didsbury & Chorlton following his departure from Huddersfield Town at the end of last season. The Senegal international is keeping up his fitness levels as he weighs up his options as a free agent. (The 72) Photo: Justin Setterfield