Zam Frederick's season-high 27 points led the Gamecocks to a victory along with good defensive play that forced 24 turnovers by the Tigers. Frederick hit 9-18 shots, including 4-10 three-pointers.
DeWayne Reed led the Tigers with 21 points and senior forward Korvotney Barber pulled in a career-high 18 rebounds as Auburn fell to 10-5.
Reed was 9-18 from the field with two assists, three steals and five turnovers. Barber, who scored six points, was 2-7 from the field. He had a dozen defensive rebounds and six on the offensive glass.
"You can't expect to win a ball game, especially on the road, against a team like South Carolina with 24 turnovers," Auburn coach Jeff Lebo said. "We made too many careless errors. Some of them were forced."
South Carolina, which improved to 12-2, trailed much of the first half, but rallied late in the half to take a 30-28 break at intermission.
Auburn came out cold to start the second period and had seven turnovers in the opening minutes of the half to help the home team pull out to a 47-32 lead.
The Tigers got the lead back under double figures on a three-pointer by Quantez Robertson at 60-53, but the Gamecocks hit their foul shots down the stretech to preserve the victory.
Auburn shot just 36.7 percent from the field and was 6-21 on three-pointers. The free throw shooting, which had improved in recent outings, was an issue on Saturday night as the Tigers made just 6-14.
South Carolina hit 46.4 percent of its shots and was 4-17 on threes while making 12-18 free throws.
Auburn out-rebounded the Gamecocks 41-34, but that was negated by the turnovers. South Carolina had six fewer than Auburn and converted AU's 24 turnovers into 25 points, something Lebo said before the game the Tigers couldn't afford to do against South Carolina's talented guards.
Tay Waller scored 12 points for the Tigers, Robertson added seven and Rasheem Barrett scored four. Nobody else scored for the Tigers, who played without 6-8 post player Johnnie Lett, who Lebo said was academically ineligible for the game. When or if Lett will be back in action yet this season is not known.
South Carolina native Lucas Hargrove had a disappointing return home. The junior forward finished the night with six points, five rebounds and eight turnovers.
Devan Downey, Dominique Archie and Austin Steed scored nine apiece for the Gamecocks. Archie added eight rebounds. Only Frederick scored in double figures for South Carolina as he finished one point shy of his career-best total.
"They hurt us in the second half really giving it to him (Frederick) and going one-on-one and we did not defend him very well there," Lebo said. "Quantez got beat about three times in a row with him taking the ball to the bucket.
"They had a stretch there for about five or six minutes where they really took the lead on us and got it out there comfortably and we really struggled for that period of time," Lebo added.
The Tigers return to action with a 7 p.m. CST home game vs. Florida on Wednesday.