The Gamecocks (12-6, 3-3 Southeastern Conference) seemed done after Kevin Knox's short jumper with 12:28 to go put the Wildcats ahead 54-40. But that's when South Carolina, fueled by the powerful, 6-foot-9 Silva, got going and outscored Kentucky (14-4, 4-2) 36-14 the rest of the way to pull off the upset.
Silva had 12 points in that stretch to lift the Gamecocks.
Wesley Myers' driving layup tied the game at 65-all and he followed that with a second straight layup for the Gamecocks' first lead of the second half, this one ruled good when Kentucky's Nick Richards was called for goaltending.
Maik Kotsar made four straight foul shots to give South Carolina a 71-67 lead and Kentucky could not respond. The Gamecocks broke a four-game losing streak to Kentucky, which managed just three points over the final 6 minutes.
Silva's tied his scoring mark set two games ago in a win over Vanderbilt.
Frank Booker added 18 points for South Carolina.
Knox led Kentucky with 21 points. No other Wildcat had more than 10 points.
