Manchester United won at the Etihad for the third time in the last four seasons to close the gap on Manchester City to 11 points, and hand them their first defeat in 22 games.
Bruno Fernandes gave Ole Gunnar Solskjaer's side the lead from the spot in just the second minute of the game after Gabriel Jesus fouled Anthony Martial in the box, Luke Shaw doubled United's lead shortly after half time.
The win did the Red Devils' hopes of securing a top-four finish a major boost – they're now eight points clear of fifth-placed Everton and unbeaten in their last 22 Premier League away games.