Manchester United fans left the Etihad before half-time after another nightmare 45 minutes.
But former director Sir Alex Ferguson had to watch the collapse with a look of lightning on his face.
Pep Guardiola’s men scored four first-half goals in a derby that completely thrashed United.
Erling Haaland and Phil Foden scored two goals each to cut through the United defense.
Sky Sports cameras showed former United boss Ferguson looking down in the stands, very disgusted by what happened on the pitch.
The Scot, who was in charge during a 6–1 defeat at Old Trafford in 2011, probably wanted to join the fans leaving the stadium.
Drone footage showed a group of Red Devil fans leaving through the turnstiles at the away ground.
At half-time, which was reminiscent of Brentford, Eric ten Hug felt helpless after four balls flew past David De Gea.
In the 7th minute, Foden fired a powerful shot that flowed into the top corner with a fluid move.
Haaland headed in the 34th minute.
Three minutes later, Kevin De Bruyne delivered a perfect pass that the Norwegian slotted into the net for a second goal.
And the fourth goal was another great reproduction of City’s football, with Haaland sliding the ball to Foden and slotting it into the goal at the far post.
Ten minutes into the second half, however, ticket buyers who left early missed a spectacular goal from Anthony that gave United a glimmer of hope.