COLUMBIA, S.C. -- Spencer Rattler had the best day of his unpredictable career, throwing for 438 yards and six touchdowns as South Carolina beat No. 5 Tennessee 63-38 on Saturday night, all but eliminating the Volunteers from the playoffs.

Tennessee (9-2, 6-2 Southeastern) might have also lost Heisman Trophy contender Hendon Hooker, who left the game in the fourth quarter with a leg injury, falling and fumbling without being hit.

Tennessee coach Josh Heupel said he didn't have an update on Hooker's status and that the team will evaluate him when it returns to Knoxville.

Even before the injury, the quarterback of the night was Rattler, who went from Heisman hopeful to the bench at Oklahoma in 2021. The junior finally lived up to the potential that fans of South Carolina (7-4, 4-4) hoped for when he arrived.

Rattler came into the night with nine interceptions and eight touchdowns and averaging 198 passing yards per game. There were questions asked about whether the Gamecocks might want to test out the backup.

But the junior was patient in the pocket, dropping passes into the narrowest of windows. He ran when he had to with five carries for 16 yards. And he even caught a pass in the red zone from Dakereon Joyner, who South Carolina typically uses as a running threat under center.

Rattler's career highs before Saturday were 387 yards against Kansas State for Oklahoma in 2020 and five TDs for the Sooners against Western Carolina in 2021.

Antwane Wells Jr. caught 11 passes for 177 yards, and Josh Vann and Jaheim Bell each caught two touchdowns for the Gamecocks.

The Tennessee defense could do almost nothing to stop the 11th-best offense in the SEC. The Gamecocks gained 606 yards after failing to get over 300 yards in three of their past four games. The 63 points are the most by an unranked team against an AP top-five opponent in the poll era, according to ESPN Stats & Information research.

"Obviously, extremely disappointed with the performance and the outcome of the football game," Heupel said. "It's everybody involved, from myself to our assistant coaches to our players, had an opportunity here and didn't take advantage of it, didn't play well. Credit to South Carolina. They did play well. Just disappointing that we didn't perform better."

Hooker was 25-of-42 for 247 yards and three TDs before his injury. There was no immediate word on the severity of his hurt leg, but he did not return to the game. Joe Milton III took over at QB for the Vols when Hooker went down, turning the ball over on downs after driving into the red zone, then leading a four-play, 75-yard scoring drive in the final two minutes.

The Associated Press contributed to this story.