I only rarely saw Mays play for the Giants - some Mets games against SF and maybe an occasional NBC Game of the Week on Saturday.
I wish the 1971 NLCS were on YouTube- Mays' Giants vs. Clemente's Pirates.
But it is hard to describe how excited the New York area was when he returned finally to playing for a NY team in 1972 for the Mets. They even made a Saturday morning cartoon about him.
He hit the game-winning - at the time go-ahead homer against the Giants in his first game as a Met. I remember watching it at 12 years old at home on TV:
https://www.youtube.com/watch?v=-1aPBAn9dQk
It was magic, that he could do that in his first Mets game, like the Baseball gods willed it as destiny.