Manchester - Paul Pogba capped Manchester United's thrilling fightback as the France midfielder struck in the closing moments to seal a 2-1 victory over Middlesbrough on Saturday.
Grant Leadbitter's second half goal put Middlesbrough on course for an unlikely win against Jose Mourinho's side, but brilliant late strikes from Anthony Martial and then Pogba saw United earn their fifth successive league win in the most dramatic fashion.
United's gritty revival maintained their momentum heading into 2017 as they look to secure a top four finish and possibly mount a late title challenge.
Middlesbrough boss Aitor Karanka was Mourinho's assistant for three years at Real Madrid and the two share a genuine friendship borne from that period between 2010 and 2013.
Their relationship was, of course, placed to one side for 90 minutes in Manchester as United were looking to go unbeaten in 12 matches, a situation Middlesbrough can only dream about as they look set for a protracted battle to beat the drop this term.
United, again missing the injured Wayne Rooney, had two early corners that amounted to nothing but it was Middlesbrough who squandered the first glorious chance just three minutes in.
Adama Traore broke through the middle and had both Stewart Downing and Alvaro Negredo free in acres of space close to the edge of the box but he opted to shoot and embarrassingly scuffed wide.
United looked to attack repeatedly early on as Antonio Valencia and Anthony Martial threatened, but they could not really trouble Victor Valdes until the 14th minute when Pogba's stunning overhead kick hit the post from close range.
Middlesbrough again showed their ability as Traore remained in heart of the action.
He beat Daley Blind and delivered a fine cross that eventually landed at the feet of George Friend, whose drilled effort was well blocked by Marouane Fellaini.
The game hit a lull as Middlesbrough looked strong at the back and United offered little, although one left footed Henrikh Mkhitaryan effort forced Valdes into a decent low save after half an hour.
United kept pushing and were unlucky not to take the lead just before the break.
Firstly, Martial rifled an effort against the post from 30 yards before Zlatan Ibrahimovic bundled the ball home past Valdes.
However, as Old Trafford celebrated, the goal was overruled as the United player was deemed to have fouled Valdes in the process of out-jumping him to score, although replays showed that Ibrahimovic had done little wrong.
Four minutes after the interval, Ibrahimovic was denied by Valdes, who saved his close-range effort with his feet while Adam Forshaw briefly threatened at the other end.
A goal was needed and few in the stadium could believe it would arrive for the visitors.
However, after 67 minutes, Leadbitter popped up to latch onto a fine Negredo knock-down header and he smashed past David De Gea.
The goal kickstarted the home side as substitute Marcus Rashford started to cause trouble.
Middlesbrough seemed determined to hold on but eventually, United's dominance proved too much.
Martial swept past Valdes to equalise after 85 minutes before Pogba scored a fine header 90 seconds later to confirm the astonishing turnaround.