If pre-match odds existed on Pep Guardiola being pushed by anyone inside Old Trafford, the overwhelming favourite would have been Jose Mourinho.
However, the Manchester United manager was well-behaved - certainly during the opening 45 minutes - and managed to steer clear of any controversy.
Instead, it was Guardiola who got himself in a touchline tussle with the United captain Wayne Rooney.
The Catalan coach attempted to prevent Rooney from taking a quick throw-in by putting the ball behind his back.
This angered the England international, who put his hands on the City boss and even gave him a little push.
Video: Rooney and Guardiola clash
Rooney avoided a booking
Rooney, looking a bit bemused after receiving the ball, must have feared a card was coming his way from referee Mark Clattenburg.
However, both the player and Guardiola escaped punishment.
They then made their peace with a quick handshake.
City led 2-1 at the break
City were already 1-0 up at the time thanks to an excellent finish by Kevin De Bruyne.
Kelechi Iheanacho then doubled the visitors’ advantage 20 minutes later before Zlatan Ibrahimovic reduced the deficit not he stroke of half-time following a mistake by City debutant Claudio Bravo.
Did Wayne Rooney deserve a booking for his reaction? Have your say by leaving a comment below.