Blackburn Rovers were controversial winners at the Riverside after a game dominated by a facial injury to Boro defender Dael Fry.
Neil Warnock’s side again had the better of proceedings before falling victim to a sucker punch by the visitors midway through the second half.
The talking point, though, came midway through the first half when Blackburn defender Jarrad Branthwaite raised his foot and kicked Fry in the face as the Boro man went for a header. Not only did it look like a clear cut penalty, it also brought an immediate end to Fry’s afternoon, who left the field with blood gushing from around his eye, leaving him to undergo treatment on several facial wounds.
It proved a pivotal moment in the contest and was one which left Warnock fuming.
Blackburn goalkeeper Thomas Kaminski was the busier of the two keepers by far and he was called upon for the first time when he reacted well to keep out an Assombalonga strike, while Sam Morsy also tried his luck.
Kaminski also had to react well after the imperious Paddy McNair picked out the run of Marcus Tavernier with a precise ball forward, but the Blackburn keeper came off his line to deny the goalscoring opportunity by collecting the ball.
Marc Bola sent an effort just wide while Joe Rothwell made a vital block to deny Djed Spence as Boro were by far the more enterprising of the two sides. Kaminski also got down well to a Tavernier drive, which was heading for bottom corner.
The woodwork came to Blackburn’s rescue as Boro continued to press for the opening goal. Jonny Howson was first denied by a great save from Kaminski after he met a McNair corner before Nathan Wood followed up and the width of the post prevented him from scoring his first goal in senior football.
And then came the sucker punch. On a rare Blackburn sortie, Harvey Elliott found space to square a ball back into the box and Rothwell was able to apply the finishing touch to fire the visitors ahead with only their second shot on goal of the afternoon.
With 20 minutes remaining, Warnock made a double-change that included a return for Ashley Fletcher, who had been sidelined through injury since September.
Blackburn did have another opportunity when Marcus Bettinelli came off his line to deny Adam Armstrong and to compound Boro’s afternoon, Tavernier was forced off with injury in the final 10 minutes.