A couple of years ago, I went to a Cal men's gymnastics event against Stanfurd, and we exited on the west side of Haas Pavilion, where Cal was playing baseball against Arizona. We reached the end of the stairs, and we were inside Evans Diamond, though we didn't have a ticket. So if there's gymnastics and baseball on the same day, save money by cutting through Haas Pavilion on the way to the ballgame.