The result caps a week in which Guardiola's side have scored 15 goals without reply, having thrashed Liverpool 5-0 last Saturday then opening their Champions League with a 4-0 victory at Feyenoord in midweek.
"It was so good," Guardiola told reporters afterwards. "Especially after an away game in the Champions League. The way we played as a team, we are so happy.
"I was lucky to manage Barcelona with many outstanding performances but this week has been a lot of goals. We have found our game, we can make short passes and we have a lot of energy from our full-backs.
"The people who come from the bench always give us something new. Clean sheets are a consequence of you controlling the game.
"You have to be serious until the end, goal difference could be important."
Next up for City is a trip to West Bromwich Albion in the EFL Cup on Wednesday night ahead of a home encounter with winless Crystal Palace in the league next Saturday.