City came into this match on the back of 12 successive victories in all competitions and extending that run was never in doubt as they took the lead after three minutes.
City extended their lead and effectively put the game to bed on 38 minutes when Raheem Sterling finished off from close range following a lovely team move.
"We were lucky to score early and after the first half we struggled a bit to break the lines," said City manager Pep Guardiola.
"The second half was much better. The start of the second half was the best and in the last 15-20 minutes we just passed the ball with no intention to attack to save energy."
That energy will certainly be needed for a crucial run of games starting with the match against Liverpool before a home encounter with Tottenham Hotspur and a trip to Arsenal.
"It is the same points, but against a [title] contender," Guardiola said of Sunday's match.
"At the end the aim is to be champion. Against teams lower in the table people can say it's guaranteed but we know how difficult it is," added the Spaniard.
"Now comes another tough, tough group of games. Today we enjoy the game, have good food and tomorrow we start to think about Liverpool."