Second-half goals from Brad Potts, Scott Sinclair and Emil Riis gave the hosts all three points as the Teessiders struggled to cause problems at the other end of the pitch.
Our Boro 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:
5. Marc Bola - 5
Looked to have settled after a tricky start but was beaten by Jayden Stockley in the build-up to the opener. 5 Photo: Clive Brunskill
6. Jonny Howson - 6
Was doing a job in Boro’s midfield before he was forced off with an injury. Boro fell apart after that. 6 Photo: Getty Images
7. Sam Morsy - 5
Was beaten to a header by Alan Browne for the opener and couldn’t get hold of the game. 5 Photo: Alex Pantling
8. George Saville - 5
Played as the most advanced of Boro’s three midfielders but struggled to make an impact behind Britt Assombalonga. 5 Photo: Getty Images