Alejandro Garnacho scored twice in the second half as Manchester United beat West Ham 3-0.
The first opportunity came in the 10th minute when Tomáš Souček headed in a corner, but his effort was brilliantly saved by Andre Onana.
However, it was the visitors who scored first when Rasmus Højlund skipped past one defender and fired home a wonderful low effort.
After the break, the Hammers had an early chance to equalize when Emerson danced into the area but fired over when it looked easier to hit the target.
And then within seconds United doubled their advantage when Alejandro Garnacho took the ball on the edge of the box and saw his deflected shot go past Fabianski.
The Argentinian youngster scored his second late in the afternoon when he pitted and fired a low drive into the opposite corner.
Man Utd player ratings
GK: Andre Onana – 7/10 – Made some important and confidence-boosting saves in the first half when West Ham arguably deserved a goal.
RB: Diogo Dalot – 7/10 – An incredible block tackle stopped West Ham pulling one back at a crucial time of the game.
CB: Harry Maguire – 4/10 – Got away with a mistake on the ball that gave West Ham the chance to equalise. Allowemd Bowen to ghost in behind him for a chance that Dalot mopped up.
CB: Lisandro Martinez – 7/10 – Played with an assuredness and control as he works his way back towards sharpness. Seeing him go off with a knee problem was a worry.
LB: Luke Shaw – 7/10 – Defended well against Johnson, particularly in the first half.
CM: Casemiro – 7/10 – Won the ball on the front foot to make the first-half goal possible. Picked out some exceptional passes too.
CM: Kobbie Mainoo – 7/10 – Continues to look completely at home at this level. Withdrawn just after the hour mark to protect him a little bit.
RM: Alejandro Garnacho – 8/10 – Grew into the game after the interval and was playing with increasing confidence after his first goal.
AM: Bruno Fernandes (c) – 8/10 – Influential and at the heart of creating chances.
LM: Marcus Rashford – 5/10 – Things didn’t quite fall for him.
ST: Rasmus Hojlund – 7/10 – Waited until Boxing Day for his first Premier League goal and is now the youngest player since Dele Alli in 2017 to score in four successive appearances in the competition.
SUB: Scott McTominay (64′ for Mainoo) – 6/10
SUB: Raphael Varane (71′ for Martinez) – 6/10
SUB: Antony (88′ for Hojlund) – N/A
SUB: Victor Lindelof (88′ for Shaw) – N/A