Nottingham Forest's relegation worries grew as Middlesbrough secured a first league win since Boxing Day with goals from Marvin Emnes and Lukas Jutkiewicz.
The hosts controlled much of the first half, taking the lead when Emnes' shot deflected in off Guy Moussi.
Jutkiewicz hammered home to double the lead, but Boro were made to sweat.
Joel Lynch's header pulled a goal back for Forest before the hosts had Kevin Thompson sent off for a second yellow, but Middlesbrough clung on.
Forest, who remain five points adrift of safety, were on the back foot during a first half dominated by Boro.
Emnes had already fired just off target before he cut in off the flank a few minutes later to see his cross-cum-shot find its way past Lee Camp off Moussi.
Jutkiewicz stroked home from just outside the box on the other side of the break, but Middlesbrough could not afford to coast after Andy Reid's free-kick was guided home by Lynch at the near post.
Thompson was red carded when he earned a second booking for an untidy challenge on Adelene Guedioura in the 75th minute.
And the Algerian international almost snatched a point when his rasping long-range effort thudded clear off the crossbar.
VIEWS FROM THE DRESSING ROOM
Middlesbrough manager Tony Mowbray:
"We worked very hard for it.
"You get a sloppy goal to concede and the sending off on the back of that left us digging in.
"The pleasing aspect is the resilience the team showed in the last quarter of an hour to see the game out."
Nottingham Forest boss Steve Cotterill:
"We deserved something. We conceded at awful times but still created enough chances - even at 2-0 down - to come back and win.
"Obviously later on, in the last 15-20 minutes or so and playing against 10 men, you're going to get create more.
"But even with the 11 on the pitch, in the second half after we dealt with the goal we were the better team."