Raheem Sterling was the match winner at the Etihad Stadium, but the City goalkeeper proved equally as vital to the victory as he made a number of important saves.
He was at his best to deny Bukayo Saka and Pierre-Emerick Aubameyang in quick succession before half-time and afterwards, Guardiola paid tribute to a consummate professional.
“Ederson is an incredible keeper for us,” said the City boss. “He is fantastic as a professional. He is so good.
“We expected it [when we signed him] but you never know. All the clubs in the world, when they sign a player, they expect the best of him.
“Sometimes they’re not professional enough or their mentality is not strong enough, but from day one, he has been so strong.
“Good moments and bad moments don’t affect him. He made an incredible two saves from Saka and Aubameyang.”
The victory was a welcome return to winning ways for City, after failing to win our previous two Premier League matches against Leicester City and Leeds.
Guardiola admitted the result was important for his side's confidence and was particularly pleased by the effort and application his team showed.
“It was an important victory,” he added.
“The clean sheet was important. But it’s not the most important thing. They fought and had the desire to win.
“It was impressive against a team that has everything to be a contender to win the Premier League.
“We knew it would be a tight game, a difficult one, but for us winning games is important for the confidence and mentality.”
Guardiola has been pleased with the start his new signings have made and he believes their stability will help eliminate the mistakes he felt cost us last season.
“Both guys, Ruben and Nathan, they don’t make mistakes,” explained Pep.
“We suffered a lot last season with the amount of mistakes we made. Still we have to improve. I have the feeling they are real defenders.
“I have to help them to build up and to create the spaces for the way we want to play. We have time to do that in training.”