
Deshaun Watson threw an 11-yard strike to Jordan Leggett, putting Clemson up 21-0 with 2:05 left in the first quarter.
South Carolina gave Clemson prime field position after a failed fake punt in their own territory.
Watson is 9-of-11 passing for 126 and three touchdowns so far this game.
That drive was five plays for 32 yards in 2:10.