Carrera scored 21 points after halftime, including 10 in overtime, when the Gamecocks (11-5, 1-2) outscored the Tigers 13-4.
South Carolina jumped out to an 11-point first-half lead, 34-23, by capitalizing on 11 LSU turnovers, but the Tigers (9-5, 0-3) closed the half with a 10-1 run to trail 35-33.
LSU connected on five of its first seven 3-point tries in the second half, including four by Anthony Hickey, who scored 18 points. He also grabbed seven rebounds, had three assists and two steals.
Unlike Saturday's home loss to Florida, when they were outrebounded 45-34, the Tigers beat South Carolina 40-36 on the boards. They lost the turnover battle, however, 22-15.