COLUMBIA, S.C. -- Imagine what the Clemson Tigers could do if they could manage to win the turnover margin on a regular basis.

Clemson committed more turnovers than its opponent for the sixth time this season on Saturday, but that didn't prevent the top-ranked Tigers from remaining undefeated with a 37-32 victory against rival South Carolina at Williams-Brice Stadium.

Quarterback Deshaun Watson rushed for a career-high 114 yards and three touchdowns and threw for 279 yards and another score as Clemson extended the nation's longest winning streak to 15 games, including a 12-0 record this season.

"We don't always play perfect, but we continue to find ways to win," said Clemson coach Dabo Swinney, whose team lost three fumbles. "If we ever win the turnover margin, we're going to kill somebody.

"But I'm proud of our team. It's not easy to win on the road and we got the result we came here for."

Clemson remained one of just two unbeaten Football Bowl Subdivision teams by claiming its first victory at South Carolina since 2007.

The Tigers, who are 12-0 for the first time since winning their first and only national title in 1981, will face North Carolina in the Atlantic Coast Conference championship game Saturday in Charlotte, N.C.

South Carolina finished 3-9, ending its season with five consecutive losses under interim head coach Shawn Elliott, who took over when Steve Spurrier resigned on Oct. 13.

It was the Gamecocks' first losing season since 2003.

"Our team fought to the very end," Elliott said. "The players believed. They came out, they fought, they made plays and they played with great effort against a great football team. They did everything in their power to go out there and defeat the No. 1 team in the nation."

But Clemson had too much savvy, too much offense -- and it had Watson, a Heisman Trophy candidate quarterback who improved to 16-1 in two seasons as the Tigers' starter.

"He was the difference in the game," Swinney said. "That's what great players do: They make everyone else better. At this stage, he's special. I think he's the best player in the country. He just doesn't flinch."

Clemson led 14-3 at halftime and took what appeared to be a commanding 21-3 lead when Watson dashed 30 yards for a touchdown early in the third quarter, but South Carolina scored on a 7-yard pass from quarterback Perry Orth to wide receiver Deebo Samuel to make it 21-10.

Then, after running back C.J. Fuller scored from 4 yards out to push the Tigers' lead to 28-10, the Gamecocks scored 14 unanswered points to keep things interesting.

Orth connected with wide receiver Pharoh Cooper for a 57-yard touchdown with eight seconds left in the third quarter. Then, after Clemson wide receiver Artavis Scott fumbled the ball following a catch deep in Tigers territory, the Gamecocks drove 26 yards in four plays, with running back Shon Carson scoring from a yard out. Backup quarterback Lorenzo Nunez added a two-point conversion run to pull South Carolina within 28-25.

But Watson -- the preseason ACC Player of the Year -- saved the day for Clemson, guiding the Tigers 60 yards in 10 plays for the decisive score. Watson completed a pair of third-down passes on the drive, which culminated with the sophomore diving in from three yards out for a 34-25 lead with 7:58 remaining.

"Our mindset was to keep doing what we were doing and not get rattled," Watson said. "We wanted to stay comfortable and stay poised, and that's what we did. They put the ball in my hands and everyone did their job and we came out with the points at crunch time."

South Carolina added a final touchdown on an 11-yard pass from Orth to Carson with one second left, but Clemson recovered an onside kick attempt on the final play.

"Considering we just played the No. 1 team in the country to 37-32 and saw the fight and effort in their eyes today, I would say (the future of the program) is in pretty good shape," Elliott said. "We all understand there are some needs to be addressed, but the foundation has been set. It's not as far off as you think."

Clemson's offense posted 515 yards -- a school-record eighth consecutive game with 500 yards -- and converted 9 of 12 third-down chances.

Freshman wide receiver Deon Cain led the Tigers with five receptions for 96 yards, including a 55-yard touchdown, and running back Wayne Gallman added 102 yards on 19 carries -- his seventh 100-yard game of the season.

South Carolina's Samuel caught five passes for 104 yards and Nunez rushed for 75 yards. Orth completed 13 of 28 passes for 219 yards and three scores, with one interception.

NOTES: Clemson has more victories against South Carolina (67) than any other school. ... Clemson DE Shaq Lawson had 1.5 tackles for loss Saturday, giving him an ACC-leading 20.5 this season. ... South Carolina WR Pharoh Cooper moved into sixth place on South Carolina's list with his 18th career touchdown reception. ... South Carolina junior LB Skai Moore led all players with 13 tackles, including 11 solo. He also forced two fumbles.