William Osula celebrates
Image caption, William Osula came off the bench to win the match late on
At a glance
Jacob Ramsey controversially sent off for second booking after referee Peter Bankes ruled he dived
Anthony Gordon scores penalty after the Newcastle forward is brought down by Bruno Fernandes inside box
Casemiro quickly equalises for Manchester United with header from Fernandes' corner in first-half stoppage time
But substitute William Osula wins it for Newcastle with brilliant strike in 90th minute
Newcastle move up to 12th place while Manchester United remain third
Substitute William Osula scored a superb late winner as 10-man Newcastle United inflicted Michael Carrick's first defeat as Manchester United manager.
Carrick grew up watching Newcastle on the Gallowgate End, and warned his players the stadium was "tough place to go" before a ball had been kicked.
So it proved - even after Newcastle midfielder Jacob Ramsey was sent off in the first half - as the spirited hosts rallied at a raucous St James' Park.
It looked like both sides were going to have to settle for a share of the spoils after Casemiro's header cancelled out Anthony Gordon's penalty.
But Osula cut inside the box and lashed the ball past the stunned Senne Lammens, who could only watch it hit the net in the 90th minute to send the stadium into raptures.
What a contrast to the scenes in first-half stoppage time when Newcastle players, staff and supporters were furious when Ramsey was sent off for a second booking.
Referee Peter Bankes felt the midfielder dived in an attempt to win a penalty when he nudged the ball past goalkeeper Lammens.
But Newcastle quickly channelled their anger and Gordon was awarded a spot-kick after the forward was brought down by Bruno Fernandes inside the box.
Gordon coolly placed his penalty straight down the middle of Lammens' goal to open the scoring and net his 15th goal of the campaign.
But Manchester United have recovered more points (nine) from a losing position than any other side in the Premier League in 2026 for a reason, and Newcastle were not in front for long.
There was still time for another dramatic twist in the ninth minute of first-half stoppage time after Manchester United midfielder Casemiro made a smart run to the near post to head home from Fernandes' free-kick.
Newcastle were quickly pegged back, but the hosts regrouped at the break and a stretching Gordon had a huge chance to put his side 2-1 up, only to fire wide at the back post in the second half.
Manchester United also had a couple of big opportunities to win it late on when Leny Yoro saw a header batted away by Aaron Ramsdale, while substitute Joshua Zirkzee was also denied by the recalled Newcastle goalkeeper.
But it was Osula who had the final say as Newcastle climbed to 12th, while Manchester United stay in third.
This day was always going to come.
The Premier League this season has been too unpredictable for Manchester United's unbeaten run to go on forever.
Carrick has had an outstanding start in charge. Now he has to show whether he can rejuvenate a losing side.
This was not quite as bad as the defeat by 10-man Everton at Old Trafford in November under Ruben Amorim, but it was poor, there is no getting away from that.
The visitors failed to impose themselves on their opponents. This was yet another game when they let them have the initiative. Once again, it took far too long for them to get going.
The issues for Carrick appear to be a series of smaller ones rather than the fundamental tactical formation as was the case in Amorim's time.
Against Crystal Palace, the attacking options from the full back areas were poor. Against Newcastle, the links between midfield and attack were non-existent.
Bryan Mbeumo and Matheus Cunha were peripheral figures. Benjamin Sesko was hardly in the game and skipper Bruno Fernandes' difficulties were highlighted by the amount of time he spent complaining. Kobbie Mainoo did not do enough to hold the midfield together.
Manchester United thought their unbeaten record under Carrick was going at West Ham before Sesko salvaged a draw deep into stoppage time. Now it has.
Aston Villa are their next opponents, at Old Trafford on 15 March. Carrick has time to sort what is going wrong out. Beat Villa and he will have one foot in next season's Champions League. Lose and questions about his suitability for the boss' role full-time will grow louder.
Newcastle host Manchester City in the FA Cup fifth round on Saturday, 7 March (20:00 GMT) before facing Barcelona in the first leg of their last-16 Champions League tie on Tuesday, 10 March (20:00).
Manchester United welcome Aston Villa to Old Trafford on Sunday, 15 March (14:00) before travelling to Vitality Stadium to take on Bournemouth on Friday, 20 March (20:00).