Newton, a sophomore quarterback splitting time with senior Dondrial Pinkins, led the only scoring drive of the second half for South Carolina (3-1). He kept the series going with a twisting 24-yard run down the left sidelines on 3rd-and-1, then finished if off six plays later when he sidestepped Troy defensive end Franklin Lloyd and zipped into the end zone for a 17-7 lead with about 17 minutes to go.
After that, it was left to the Gamecock defenders to stop Troy (2-2) - and help "Pops" Frisby get his first crack at college football.
However, the Trojans, who made their bones this season with a 24-14 victory over then 19th-ranked Missouri, were far from finished.
They drove to South Carolina's 30 on their next series. On 4th-and-4, though, Aaron Leak had to throw a desperation floater to avoid a sack and, despite a lunging dive by receiver Jason Samples at the goal line, the ball fell incomplete.
Troy had one last chance, reaching South Carolina's 11 with three minutes left. But Leak was picked off by South Carolina linebacker Lance Laury with 2:13 left.
The Trojans were held to 207 yards, their lowest total this season.
With Troy out of timeouts, South Carolina coach Lou Holtz called on "Pops" - the Gamecocks 39-year-old walkon receiver Tim Frisby. Frisby, recently retired after 20 years in the U.S. Army, got in for the final four plays - split wide to the right on four runs up the middle - as South Carolina ran out the clock on the victory.
Newton finished 10 of 14 for 98 yards passing. Pinkins was 6 of 10 for 101 yards. Each threw an interception.
Troy Williamson had six catches for 105 yards.
South Carolina looked like it would take control early. Pinkins, starting again after sitting out last week with a shoulder injury, connected with Williamson on a 61-yard pass, then ran 13 yards to Troy's 6. Cory Boyd finished the drive two plays later with a 3-yard TD, the third time in four games this year South Carolina scored on its first possession.
Then things got hairy.
Pinkins couldn't handle a shotgun snap deep in his own territory and defensive end Larry Brown covered up for the Trojans on South Carolina's 18. DeWhitt Betterson had runs of 10 and 3 yards on the drive, the last for the tying touchdown.
Gamecock fans and coaches spent the week debating if Pinkins or Newton should start at quarterback after throwing for 324 yards in last week's 34-3 win over South Florida. It didn't seem to matter much as neither could do much against Troy.
Newton was picked off to end one drive. A chop block on South Carolina center John Strickland wiped out first-down yardage on the team's next possession.
It took a bad error by Trojans' Joel Whinghter - roughing the punter on South Carolina's 20 - to keep the Gamecocks moving. Josh Brown hit a career-long 40-yard field goal with 19 seconds to play before halftime and sent South Carolina off with a 10-7 lead.
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