Mariano Rivera played his first game at Fenway Park on July 16, 1996. He was a setup reliever then and pitched two innings against the Red Sox. Joe Girardi, who manages the Yankees now, was the catcher.
John Basmajian can’t remember for sure, but he probably was at the game that day. The guy everybody at Fenway calls “Baz” has been working at the park for 46 years selling tickets.