City were the dominant side throughout the game and ran away with a 3-1 win.
But Ederson taunted their rivals by saying it could have been more goals if the team had pushed further.
City began the game with a flourish, but took their foot off the pedal until half time.
"We were way better than United," Ederson said to reporters after the game.
"If we had pushed more we could have got a larger result."