Manchester United scored two goals in two minutes late in the second half to beat Middlesbrough 2-1 at Old Trafford in the Premier League.
With United trailing with five minutes remaining, Anthony Martial levelled with a finish from inside the area, before Paul Pogba's finely-placed header gave the hosts all three points just moments later.
Zlatan Ibrahimovic had a goal controversially ruled out for a high foot in the first half, while Grant Leadbitter put Boro ahead midway through the second half before the dramatic finish.
The result gives United their fifth straight Premier League victory to end 2016 on a high, while Boro are 16th, four points clear of the drop zone.
Jose Mourinho made five changes from the side that beat Sunderland on Boxing Day, bringing in Anthony Martial, Henrikh Mkhitaryan and Marouane Fellaini, while in-form centre-backs Marcos Rojo and Phil Jones were replaced by Chris Smalling and Eric Bailly.
Adama Traore had an early chance for Boro, poking wide from 20 yards despite having team-mates either side of him as the visitors ran through three-on-one.
United then hit the post through Pogba, whose overhead kick from Mkhitaryan's header across goal had Victor Valdes beaten but not the woodwork, while George Friend saw a volley blocked by Bailly after fine work from Traore on the right byline.
Valdes then saved well from Mkhitaryan's snap-shot from outside the box and Martial hit the post with a wonderful 25-yard effort, before controversy arrived with five minutes of the first half remaining.
Getting up to poke home Martial's fine left-wing cross, Ibrahimovic's strike was ruled out by referee Lee Mason for a high boot, despite not making any contact with goalkeeper Valdes.
Valdes denied Ibrahimovic after the break from close range after Pogba had fed the Swede, before Boro broke the deadlock on 67 minutes.
Latching onto Alvaro Negredo's superb knock-down, Leadbitter slotted past David De Gea from 12 yards to send the travelling fans wild.
Ibrahimovic nearly levelled straight away, but was again denied by Valdes low down as the ball broke to him in space in the area, while the Spaniard was at his best again to deny substitute Marcus Rashford's volley.
Martial missed a fine chance to equalise with eight minutes remaining, failing to beat Valdes in acres of space after Mkhitaryan's superb through ball, but the Frenchman got his goal three minutes later.
It was a long ball that broke Boro open, as Ibrahimovic's flick on was finished off by Martial, who wrong-footed Valdes from 12 yards out.
Boro had a penalty shout seconds after the equaliser as Bailly nudged Gaston Ramirez, but Mason waved play-on to allow United to break for their winner.
Pogba had plenty to do as he received Juan Mata's cross from the right, but positioned a fine header into the right corner from 10 yards as Old Trafford erupted.
That's how it stayed, as Mourinho consoled his friend and former Real Madrid colleague Aitor Karanka at full-time.
Player ratings
Man Utd: De Gea (6), Valencia (6), Smalling (6), Bailly (6), Blind (6), Fellaini (6), Herrera (7), Martial (7), Pogba (6), Mkhitaryan (8), Ibrahimovic (6)
Subs: Rojo (6), Mata (6), Rashford (6)
Middlesbrough: Valdes (8), Chambers (7), Bernardo (6), Gibson (7), Friend (7), Leadbitter (7), Forshaw (6), De Roon (6), Traore (7), Downing (6), Negredo (7)
Subs: Clayton (6), Ramirez (6), Fabio (NA)
Man of the match: Henrikh Mkhitaryan