The loss dealt another blow to Pep Guardiola’s side’s Premier League title aspirations, with Nicolas Otamendi’s late header unable to inspire a dramatic fightback.
READ | City beaten in Manchester derby
The Argentine nodded home from a corner with five minutes remaining to give City hope, but United held on as we threw everything at an equaliser.
Rashford had given the visitors the lead from the penalty spot, converting after Bernardo Silva’s foul on him and six minutes later Anthony Martial netted what would prove to be the winner when his low drive crept inside the post.
It was a frantic game in which City had a couple of penalty appeals waved away.
United looked to play on the counter-attack throughout and it allowed the hosts to create a raft of chances, with Kevin De Bruyne, Rodrigo, Gabriel Jesus and Riyad Mahrez all going close, but it was to no avail on a disappointing evening at the Etihad.
See the best images from the game in the gallery below.