The result leaves Chris Wilder's side in eighth place in the second tier table, but they're just two points off the play-off places with a game in hand as things stand.
Speaking after their loss to the Rovers, Middlesbrough' s manager said: “For me, they dominated the first half and from an attitude point of view more than anything. They set themselves up for a deserved win.
“We’ve had a couple of chances late on, a reaction at half-time. I’m not one for players needing a word or two. At Blackburn away when it’s third vs seventh and going into the second part of the season.
“There’s a saying, fire and ice mentality. Without the ball, fire and desire to get it back, and then the ice to calm yourself down and play your game. But the first has to be the fire and I thought Blackburn had it first half, and we were always chasing it.
“Second part of it, with the football, we weren’t very good as well. Thought we were better second half, created two fabulous chances, but I want more, expect more and demand more, especially from the off.”
Next up, Boro host fellow promotion chasers Coventry City at the Riverside Stadium this weekend, in what looks set to be a real six-pointer in the battle for the play-off places.
Take a look at today's biggest stories from the Championship, as the January transfer window speculation and build-up to this weekend's action continues:
“We’ve had a couple of chances late on, a reaction at half-time. I’m not one for players needing a word or two. At Blackburn away when it’s third vs seventh and going into the second part of the season.
5. Cherries want cut-price Moore
Bournemouth are said to be readying a move for Cardiff City striker Kieffer Moore. The Wales international had a hefty £10m last summer, which put off Wolves, but he's likely to be available for a more reasonable fee this month. (Wales Online)
Photo: Tony Marshall
6. Salford keeping tabs on Vale
Salford City are said to be plotting a move for Blackburn Rovers striker Jack Vale. He's currently on loan with National League side Halifax Town, and had a spell with League One side Rochdale last season. (The 72)
Photo: Cameron Smith
7. QPR win race for Sanderson
QPR have beaten Sheffield United to the signing of Wolves defender Dion Sanderson on loan. The towering centre-back spent the first half of the campaign on loan with Birmingham City, where he made 15 Championship appearances. (Club website)
Photo: Ashley Allen
8. Blades keen on Reds duo
Sheffield United look set to up their efforts to sign a new centre-back, and Liverpool duo Rhys Williams and Nat Phillips are both said to be of interest. The Blades signed goalkeeper Adam Davies from Stoke City yesterday afternoon. (Daily Mail)
Photo: Alex Livesey