Man Utd Man City tunnel fight: Milk on Mourinho - Twitter reacts
Goals from David Silva and Nicolas Otamendi either side of Marcus Rashford’s strike secured three points for Pep Guardiola’s side, sparking wild celebrations in the tunnel.
Manchester United boss Mourinho reportedly took offence to City’s loud celebrations, approaching the away changing room and asking them to turn down their music and show "more respect".
The Portuguese manager is said to have had milk thrown at him after a bust-up with goalkeeper Ederson, while Mikel Arteta was left with a cut to his head and blood streaming down his face.
Fans of both clubs have got involved on Twitter, while Arsenal supporters have also been wading in after the infamous ‘battle of the buffet’ back in 2004.
Take a look through the gallery above to see some of the best reactions as Manchester United and Manchester City were involved in a scrap in the Old Trafford tunnel.