Tebow, wearing his familiar No. 15 jersey, hit a 91-mph fastball over the left-center field wall for a homer on Wednesday and was greeted at home plate by teammates in Port St. Lucie, Fla.
The 29-year-old Tebow, a 255-pound outfielder, is likely the oldest player playing in instructional league games in Florida. He signed a $100,000 minor league contract with the Mets on Sept. 8 after holding a workout in Los Angeles on Aug. 30 with 46 scouts in attendance.
Tebow, a former Heisman Trophy winner, two-time national champion at the University of Florida and NFL quarterback, hit the homer on the first pitch of his professional baseball career against a team of St. Louis Cardinals farmhands.
In the storybook moment, Tebow's home run came off 6-foot-5 left-hander John Kilichowski, who was drafted by the St. Louis Cardinals in the 11th round out of Vanderbilt University in June.
Kilichowski was 12 years old when Tebow helped the Gators to the first of two national championships in 2006. Tebow grounded out in his second at-bat.
After signing with the Mets, Tebow also signed a direct marketing deal with Majestic sports apparel to permission the company and Mets to market his No. 15 jersey.
On his second day in instructional league camp last week, Tebow had the No. 1-selling jersey on MLB.com.