City jumped to a 5-1 lead before the Cottagers struck three times. However, with 15 minutes remaining, Fulham couldn't find an equaliser.
“I know you’re going to ask what happened, but I don’t have an answer,” said Guardiola afterwards.
“Football is emotion - all the goals were bad defending, we got so deep to defend these kinds of crosses, we have to occupy the spaces a bit better.
“But we made incredible things today because I know how difficult (Fulham are) - the way we defend and the other ones.
“But after that Erling (Haaland) had to make the 6-3 but hit the post and immediately it was 5-4.
“When that happens it’s a question of survive. Don’t tell me how, we need a bit of luck and at the end we take it.”
On Erling Haaland reaching 100 Premier League goals in record time, Guardiola also said: “When I arrived if you told me that in 111 games, he scored 100 goals, I’d say, ‘Are you sure?’ In this league? But he did it. The numbers are insane. Insane.
“For sure he’s one of the best Premier League strikers of all time. For the strikers, it’s a question of numbers and his numbers have no discussions.
“You are British right and you bring the best strikers to this country, so Erling is one of them.
“I am happy for him and happy for the team to deliver this day for him."