The Giants teamed up with TaylorMade Golf for the event, which took place before batting practice prior to the game against the Astros. Johnson hit balls with his driver from home plate and was later joined by Giants players and personnel, who tried their hand at sending golf balls toward McCovey Cove.
"If it was a baseball, I'd be a little nervous, but a golf ball, I can handle that," Johnson said.
After Johnson, Wednesday starter Matt Cain wowed the crowd with an especially long drive on his only swing -- only after Giants general manager Brian Sabean jokingly said he was going to go back inside if Cain took a swing. Sabean was seen jokingly looking away as Cain swung.
"One swing was enough for him," manager Bruce Bochy said.
In February, Cain's golf swing caught the attention of the golf world at the AT&T Pebble Beach National Pro-Am's celebrity shootout when he hit a 330-yard drive.
"I knew he was a pretty good golfer. They were telling me about that before," Johnson said.
Johnson, who played baseball up until high school, said he occasionally finds his way into batting cages.
"If I wasn't playing the U.S. Open tomorrow, I'd probably [take batting practice]," Johnson said.