City won 6-0, with Ait-Nouri outstanding at fullback and Echeverri scoring in the rout.
On new signing Ait-Nouri, Guardiola said: “Wow, he played very good because we had to defend a back four and then a back five, he had to arrive in the end.
“At the end he played really good. It’s his first game but he’s played in the Premier League for many years.
“He can help us play in that important role, then he went holding midfield in the pockets, he moves really well in small spaces.
“He’s intelligent and clear to defend and take the ball and especially in the final third he’s so clever as well.
“I was really pleased for the game he played.”
Echeverri deserved his goal
Guardiola was also pleased with Echeverri's goalscoring display.
“Since he’s arrived the previous season, three or four months with us at the end of the training session he’d practice the free-kicks with the keeper and the wall alone. The others didn’t,” he added.
“He practiced and practiced, and the work paid off, he had the courage and quality. When you practice, it’s like golf or basketball, the more you practice the more chances you have. It was a fantastic goal and he’s an incredible player in the small spaces.
“Unfortunately, he couldn’t continue after half-time for a problem with the ankle but it was really good that his first minutes in this competition, he made a fantastic goal. The free-kick was really, really good.”