This saw Pep Guardiola’s side return to the top of the Premier League table, leading Liverpool by one point.
And they have Bernardo Silva to thank, scoring the first goal after 53 minutes.
But footage from the game shows how easy it was for the Portuguese star to score.
In the clip, David Silva is roaming into United’s half with the ball.
And the Spaniard manages to find a pass between Marcus Rashford and Paul Pogba.
The ball comes to Bernardo Silva, running through on the left wing.
Luke Shaw is the only defender in his way – but he does not do much defending.
Shaw’s error comes as:
The midfielder roams straight into the penalty box, keeping the Englishman back-pedalling.
With a feint to his left, the 24-year-old then drives the ball into the bottom-right corner.
De Gea cannot reach the ball as it trickles into the goal.
Old Trafford falls silent as the City players celebrate the lead.
Leroy Sane added another 12 minutes later.
This footage was shared on Twitter, where it has been viewed nearly 5,000 times.
And the United faithful put the blame for conceding at Shaw’s door.
“Shaw is absolutely c***,” one supporter said.
Another commented: “Luke Shaw can f*** off.”
While a third suggested the full-back should have no further part to play at United.
“Shaw needs to be out of the door and replaced”
Man Utd fan
“Man Utd have a lot of cleaning to do,” they said.
“Shaw needs to be out of the door and replaced.”
And a fourth added: “Shaw needs to be axed.”
While a fifth said: “Shaw has been absolutely shocking.
“Another one I’d flog off in the summer.”
This comes as fans were furious with the decision to start one player against City.