Nottingham Forest's seven-match unbeaten run was brought to a grinding halt as their former striker Britt Assombalonga helped Middlesbrough to a 2-1 win at the City Ground.
Middlesbrough spent £15m to sign the striker from Forest in the summer of 2017 and the forward came up with the goods as he put the visitors ahead with a calm finish early on.
George Saville added the second five minutes into the second half to put Neil Warnock's side in control.
Loic Mbe Soh headed home in the 93rd minute to make it 2-1 as he attacked a cross from fellow sub Joe Lolley. But there was still time for more drama as Yuri Ribeiro was send off following a tussle with Saville.
Chris Hughton's side had looked like they had turned a corner, having embarked on an unbeaten run that lifted them away from the bottom three, but it was Middlesbrough who took three points to bolster their play-off push.
Paddy McNair had a shot charged down in the penalty area following a short-corner routine, while Marcus Tavernier forced an uncertain save from Brice Samba with a driven effort, as Middlesbrough made a bright start.
Forest responded as Sammy Ameobi's trickery on the edge of the box gave him the room to shoot – only for him to blaze high and wide.
It was deserved when the visitors took the lead in the 14th minute, as Jonny Howson delivered the perfect pass for Assombalonga to apply a simple, composed finish from eight yards, against his former club.
Some determined work from Ameobi and some quick feet from Lewis Grabban ended with the striker firing a tantalising low cross right across goal, but it went unconverted.
Boro could have gone 2-0 ahead when Assombalonga rattled the post with a fierce effort, which was only kept out when it bounced off the woodwork and onto keeper Samba's head, deflecting it away off the line.
By half time Forest were a little fortunate only to be a goal behind, with Middlesbrough having been a constant threat from set-pieces.
Forest made a change at the interval, with striker Lyle Taylor replacing midfielder Samba Sow who had been walking a disciplinary tightrope having been booked.
But it was Boro who were to extend their advantage within five minutes of the restart as Assombalonga led a quick break, which saw Marcus Tavernier slide a perfect pass to Saville, who kept his head to slot the ball beyond Samba when one-on-one with the keeper.
Marc Bola almost made it better for Middlesbrough when he rattled the bar with a powerful shot.
Mbe Soh's goal gave Forest hope in injury time but that was ended when Ribeiro was red carded.
