The Tigers (16-10, 6-6 SEC) won a league game on the road for the first time this season and stretched their SEC winning streak to three games, their longest since rattling off 13 wins in a row in 2009.
LSU saw an 11-point lead slip to 56-52 after Malik Cooke's consecutive 3-pointers with 4:07 to play. But Hamilton put back Warren's miss and a South Carolina turnover led to Ralston Turner's third 3-pointer of the day to give the Tigers back their comfortable margin.
The Gamecocks had no answer for LSU's inside game. The 7-foot Hamilton hit 5-of-8 floor shots while Warren made 6-of -10 shots, most from close in. Johnny O'Bryant made 4-of-5 baskets in the second half.
Cooke had 17 points for the Gamecocks (10-16, 2-10).
LSU had a seven-point lead cut to 38-36 when South Carolina freshman Brenton Williams was called for a technical foul for hanging on the rim after his breakaway dunk. Andre Stringer made two foul shots and O'Bryant had three consecutive inside baskets to push LSU ahead. After Stringer hit a jumper and O'Bryant another uncontested shot inside, the Tigers were ahead 50-39.
Anthony Hickey had 10 points, 7 assists and 6 rebounds for LSU.
No one else on South Carolina reached double figures. Bruce Ellington, the team's second leading scorer, was only 3-of-12 shooting for 6 points — four fewer than his average.
LSU and South Carolina both hoped to capitalize on recent success after awful starts to the SEC season.
The Tigers began 2-5 in the league, yet have won three of their last four including a 69-67 overtime win against Mississippi State on Tuesday. The Gamecocks, who opened 1-9 in the league, broke a five-game losing streak Wednesday, 57-56, against Georgia and were looking for their first two-game SEC win streak since January 2011.
Neither club was all that sharp in in the opening period.
South Carolina hit three of its first nine shots as LSU moved in front 15-8. Then the Tigers went cold for nearly 7 minutes and the Gamecocks moved in front 20-17 off a 12-2 surge.
LSU found its range late as Hickey pushed the pace. He hit a tying 3-pointer, then fed a wide-open Warren for an easy bucket underneath. Hamlton converted two foul shots and Hickey closed the 8-2 run with another foul shot to put LSU ahead 25-22 at the break.
Still, the Tigers were just 4 of 15 from the field the half's final 14 minutes after hitting five of their first eight shots.
Ellington struggled in the opening period as he made just one of his six attempts. South Carolina was 1 of 8 from three-point range.