The 20-year-old Blues star followed his late winner in the first leg last week with the clincher in the Westfalenstadion as the Blues came from behind to win 2-1 and set up a semi-final against Paris St Germain.
And, while Foden has been growing in stature and influence steadily since he made his City debut aged 17, Guardiola felt that those two games are a watershed moment for the youngster, who rushed across to celebrate with his manager after thrashing in the stunning winner.
Guardiola said: “You have the feeling that he is a guy who never hides. He always creates something.
“He is dynamic offensively, defensively with quality in the smaller spaces. He is learning right now not to take just one touch, he is able to make more touches when making decisions.
“He scored two important goals, the second goal in the Etihad and today helped us to be in the semi-final.”
Guardiola was told about Foden’s potential when he took over the reins at City in 2016 and has carefully nurtured his talent, despite the impatience of some critics.