The Tigers (8-13, 1-6) lost their first six SEC games by an average of more than 12 points and appeared on their way to another double-digit league loss as South Carolina (12-7, 3-3) cruised to a 15-8 lead.
But the Tigers went on a 17-5 run, taking a lead they would not relinquish.
Auburn's stifling zone and sharp defensive pressure made the difference. South Carolina shot 7 of 33 from outside the arc and managed just 20 points in the paint.
The usually poor shooting Tigers also made 26 of their 34 free throws.