Markeshia Grant added 11 points, including three 3-pointers, and Ieasia Walker chipped in 10 points for the Gamecocks (20-7, 9-5 Southeastern Conference).
The Gamecocks completed the regular-season sweep of the series against the Crimson Tide, using a 21-6 first-half run to pull away early. That spree turned a 9-8 Gamecocks lead into a 32-16 advantage, and they took a 12-point lead at halftime.
South Carolina outscored Alabama 31-29 in the second half to seal the win.
Jasmine Robinson had 17 points to pace the Crimson Tide (12-16, 2-12).