Damien Leonard (6-5) of J.L. Mann had planned to wait until next Thursday to announce a commitment to South Carolina.
But word leaked out earlier Thursday, so Leonard is confirming that he actually committed to Darrin Horn last week. He has canceled a scheduled visit to Oklahoma State.
Leonard had been favoring the Gamecocks for several weeks.
"They don't really have a shooter, and I feel like I can go in and make an impact," he said. "I'm comfortable with the players and I feel like we can play together."
Leonard appeared to be headed to Clemson early in his recruiting, but that changed after Oliver Purnell left for DePaul. USC, Arizona and Oklahoma State eventually moved to the top of his list.
He made his official visit to USC for the Georgia football weekend, and that visit sealed in his mind the decision to join the Gamecocks.
"They have a good business program which is my major," Leonard said. "The coaching staff is outgoing, and I feel like I can trust them with the promises they made me."
Leonard is regarded as the state's top prospect for 2010-11. He averaged 21 points, 6.5 rebounds and 3 assists per game last season.
He's the second commitment for the 2011 class and third member of the class overall.
He will join 6-8 Anthony Gill and transfer 6-7 Murphy Holloway as Gamecock newcomers in 2011.