Penalties, bad plays and too many mistakes to count: All things that No. 6 Clemson seems to save for playing rival No. 10 South Carolina.

It happened to the Tigers (10-2) for a record fifth consecutive time against the Gamecocks on Saturday night in a 31-17 loss that dropped Clemson coach Dabo Swinney to 1-5 in the game his fans care most about.

It also left record-setting quarterback Tajh Boyd winless in four rivalry appearances and star receiver Sammy Watkins without a touchcown in three games against South Carolina.

"I know it is a rivalry. I know it is not supposed to be this way," said a disappointed Boyd. "But Clemson will beat South Carolina again. It is just a question of which team does it."

And how long that could be?

Former Clemson coach Tommy Bowden's tenure appeared over several times during his 10-season run from 1999-2008. A big reason he lasted so long was his 7-2 career mark against the Gamecocks (10-2).

Bowden's successor, Dabo Swinney, won the 2011 Atlantic Coast Conference champion, won two other ACC Atlantic divisional crowns and has posted three straight double-digit win seasons for the first time at Clemson since 1987-90.

This season started with a 38-35 win over then fifth-ranked Georgia and a 6-0 run that had the Tigers in the national championship mix until a 51-14 loss to No. 2 Florida State, the most points the team had ever allowed at Death Valley.

Clemson had won four straight since and hoped to ease the sting of Florida State with a victory at Williams-Brice Stadium.

"I wish the two losses were different. It's a big rivalry game for us," Swinney said. "Three 10-win seasons in a row, nobody wants to hear it now, but you've got to have some perspective."

The Tigers might still wind up in the BCS if the ACC-friendly Orange Bowl takes them if Florida State plays for a national title.

Clemson had eight penalties, including an offside on fourth-and-1 that kept South Carolina's go-ahead touchdown drive going. South Carolina held the ball nearly 17 minutes longer than the Tigers. And then those turnovers.

"Mental toughness, physical toughness has nothing to do with it," Clemson defensive lineman Grady Jarrett said. "It's just failed execution. It is just us performing on game day."

South Carolina quarterback Connor Shaw threw for one touchdown and rushed for another to lead South Carolina.

"Connor Shaw, ah man, the best quarterback in school history," Gamecocks coach Steve Spurrier said. "He's probably the difference maker completely for us."

Gamecock players rushed to the student section in celebration of the unprecedented win. They'd hoped to have more to celebrate as Southeastern Conference Eastern Division champs, but No. 5 Missouri defeated No. 19 Texas A&M 28-21 about 45 minutes after South Carolina's win to eliminate the Gamecocks (10-2).

Shaw moved to 26-5 all-time as a starter and ended his career a perfect 17-0 at home in the sweetest way possible.

"This is why we came to South Carolina," Shaw said.

Clemson still leads the series 65-42-4.

"We've been achieving things no one at South Carolina's done before," cornerback Victor Hampton said. "I told the boys, 'Don't stop at five.' Keep going."

There's no reason to think they won't — and using the same formula of ball control and timely turnovers.

South Carolina forced six turnovers, four of them in the final quarter as Clemson tried to rally back after Mike Davis' 2-yard TD run broke a 17-all time with 11:47 to go.

"Just give them credit. We never had six turnovers before," Swinney said. "That wasn't part of the script."

The Gamecocks have a chance at a third straight 11-win season in their bowl. They had just one 10-win season in their history before Spurrier arrived after the 2004 season.

South Carolina put things away with two touchdowns in the fourth quarter to break away from 17-all tie. After Davis' TD, Pharoh Cooper threw a 26-yard TD pass to Brandon Wilds that put things out of reach.

Clemson left the field defeated again and wondering why an offense that sets records in every other game struggles at the hands of its rivals.

"They're a good team that continues not playing very well against us," Spurrier said.