Matty Longstaff’s early strike put the visitors ahead at Old Trafford, but Anthony Martial levelled the scores soon after.
A defensive error then allowed Mason Greenwood to thump home a second before a fine header from Marcus Rashford left Newcastle with a mountain to climb in the second half.
When Martial pounced to lift home his second of the day on 51 minutes, the victory for the Red Devils was sealed, leaving United with little festive cheer.
Steve Bruce’s men will now look to respond with their second game in the space of 48 hours, when they take on Everton at St. James’ Park on Saturday.
The hosts began with purpose in the opening exchanges, with Rashford seeing a deflected free kick flash over before Harry Maguire’s header from the resulting corner took a touch on its way over.
The first real opening, though, was created by the Magpies. After Miguel Almirón cleared the crossbar, United came again and Joelinton’s fine through ball released Dwight Gayle. The frontman – on his first Premier League start of the season – looked as though he was about to net at the Stretford End, just as he had done two seasons earlier, but his left-footed finish was too high.
But Newcastle had found their feet by then, and after 17 minutes they moved in front. It was another goal to remember for Longstaff, after his winner against the same opposition at St. James’ Park back in October on his league debut, but it owed much to the work of Joelinton. Gayle’s pass found Longstaff in space and his lofted pass played in the Brazilian, who held off his man and laid it back into the path of the 19-year-old. Longstaff sidestepped Luke Shaw and buried his shot beyond David de Gea, sending the travelling support into raptures.
It proved to be a lead they couldn’t hold. Fred had tested Martin Dúbravka for the first time with a drive soon after the opener, but the Slovakian wasn’t able to get more of a hand to Martial’s low shot seven minutes later, and it crept into the corner.
Andreas Pereira and Rashford both tried their luck as the balance of power shifted in favour of Ole Gunnar Solskjaer’s men, but it was a mistake from the visitors which helped them into the lead. Fabian Schär’s misplaced pass gave Greenwood a sight of goal around 20 yards out and his strike cannoned in off the crossbar, via a fortuitous deflection.
Dúbravka palmed away a Pereira free kick as the Red Devils began to push for a third, which duly arrived before the break. Matty Longstaff felt Scott McTominay had caught him with a stray elbow, but play continued at pace and Aaron Wan-Bissaka’s cross was met by Rashford, whose emphatic header left Newcastle with a sizeable task ahead of them.
And that task looked even more daunting six minutes after the restart. Sean Longstaff’s pass didn’t make it all the way back to Dúbravka from near halfway, and Martial nipped in to run clear, dinking in his side’s fourth of the afternoon.
Paul Pogba, on for McTominay at the break, saw a curling effort kept out and Martial went close to a hat-trick when his shot came back off the base of the post soon after. At the other end, it just didn’t happen for Bruce’s side, though Sean Longstaff went close to pulling one back on a miserable day for the Magpies.
After nutmegging Fred, the midfielder’s shot was too high, and Newcastle – who now face the Toffees at the weekend, looking to extend their lengthy unbeaten home record – left empty-handed.
