The two giants shared six goals at the Santiago Bernabeu for the first-leg of their quarterfinal.
Juventus great Del Piero said: "Perhaps it was one of the best matches in the history of the Champions League. For the level of play, for the beauty of the goals.
"When there are matches of such great importance we tend to hedge a a little more and instead we saw two teams facing each other head-on. This match needs to be replayed many times throughout the week.
"Guardiola didn't see a bad thing about Foden, he has incredible qualities. Pep trains you to do this and if you're at City it means you're good enough to do this. But then in that goal there's a bit of a summary of his qualities, he's bold and wise."