CLEMSON — South Carolina’s best defense came on offense Saturday night at Death Valley. By piling up 86 plays and possessing the football two seconds shy of 40 minutes, the Gamecocks kept the Clemson offense from being more of a factor in their 27-17 victory.

“We were hoping it would be that kind of game. It worked out the way we hoped,” USC coach Steve Spurrier said. “We made a bunch of third downs there, and that was the big difference in the game.”

USC, which finished the regular season at 10-2 by defeating its rival for a fourth consecutive season, converted 11-of-21 third downs as well as its only fourth-down attempt. By continuously moving the chains, quarterback Dylan Thompson, who completed 23-of-41 passes for 310 yards and three touchdowns, and his offensive teammates made sure the Tigers couldn’t get their high-powered attack in gear.

“That was huge,” Thompson said. “Coming into the game, that was our goal — to keep their offense off the field. They’re dangerous, and they’ve got great players. I think we did a good job of that.”

Wide receiver Ace Sanders, who caught six passes for a career-high 119 yards, including a 34-yard touchdown reception to start the third quarter, could see the deflation in the Clemson defenders as USC kept racking up first downs — 26 in all.

“We wanted to show that our offense is not just dependent on our defense. We can also play on our side of the ball, too,” Sanders said. “You keep picking up first down after first down after first down, and that can wear out a defense.”

That proved especially true in the third quarter, when the Gamecocks ran 21 more plays than the Tigers and possessed the football nearly 12 of the 15 minutes.

“We couldn’t get the ball in third period. We just couldn’t stop them on third down,” Clemson coach Dabo Swinney said. “The third quarter was huge. We had too many penalties, too many turnovers, and South Carolina did a great job of controlling the ball.”

USC outscored the Tigers 17-3 in the second half, with the back-breaking touchdown coming on a 6-yard pass from Thompson to receiver Bruce Ellington with 4:17 left to play. That score was set up by a brilliant 20-yard run on a quarterback draw by Thompson on third-and-19 that carried to the Clemson 6.

The offense always seemed to come up with key conversions when it needed them most. That clinching drive also included USC’s only fourth-down conversion, a 1-yard sneak by Thompson that gave the Gamecocks a first down at the Clemson 17.

Thompson, who added 38 yards rushing while outplaying Clemson’s Heisman Trophy candidate Tajh Boyd, credited Spurrier for making good decisions.

“Luck is always there, but mainly it’s just good play calls,” Thompson said. “It seemed like somebody was wide open every time we had a third down, looking back at it. The run plays that coach called were great.”

Thompson, whose only other start this season came in the win against East Carolina in the second game, was ready to step in for the injured Connor Shaw, who was nursing a sore foot.

“I was confident,” Thompson said. “I knew that my O-line was with me, these guys were with me, Ace and Bruce and Nick (Jones). And (tailback) Kenny Miles, you can’t say enough about him. Everybody was just so encouraging. You don’t really get nervous when you have everybody behind you.”

Sanders said the players had plenty of faith in Thompson’s ability.

“He kept everybody calm and everybody collected. Like he said, we all had his back,” Sanders said. “We knew what he was capable of, and we just followed him.”

All the way up and down the field.