Hornets defender Craig Cathcart scored the only goal of the game when he headed home with just 11 minutes on the clock.
Our Boro writer Joe Nicholson has dished out his marks following the match – scroll down and flick through our picture gallery to see if you agree with his player ratings:
9. Marcus Tavernier - 6
Looked lively early on but faded a little in the second half. Worked hard but his influence waned. 6 Photo: Clive Brunskill
10. Ashley Fletcher - 6
Played some neat touches in the final third and forced a save from Ben Foster in the first half. Didn’t receive a clear goalscoring opportunity. 6 Photo: Alex Livesey
11. Britt Assombalonga - 6
Bevered away and saw a few efforts saved by Foster. Headed over late on. 6 Photo: Jan Kruger
12. Lewis Wing - N/A
(for Saville, 77) - Came on as Boro pushed for an equaliser. N/A Photo: Harriet Lander