Ilkay Gundogan, Phil Foden, Erling Haaland and James McAtee scored on the night, with City also hitting the post four times.
Afterwards, Guardiola said: "You have to do what you have to do.
"It's a joy to be manager of this team. I love it, I love them.
"To come here with this incredible respect and run and the beginning until 0-2 was easier because they were more open, after that they sat back with what has happened lately with most teams - 18 players in the box so it's not easy.
"But we created a lot of chances and I feel we are improving step-by-step how we attack them but we still miss one or two actions.
"No injuries, players who didn't play lately had a lot of minutes so a really good night. Just dinner and recover and our last game before the international break."
On substitute McAtee, Guardiola also said: "Everyone adores him, you have seen the reaction of the players so everyone loves him.
"I have the feeling the same as in the beginning. With teams who play so deep he has the quality to find it.
"He scored and had a few more chances. I always had the feeling that I believe more he can play here than he does. Hopefully minutes can help him and show that he is part of that.
"Of course, he will not be a regular player this season but in a lot of games he will help us and when he plays like he did today I can always count on him perfectly."
