In what was forecasted as a battle between two defensive-minded squads, South Carolina prevailed with four players scoring in double figures led by guard Jamel Bradley's 16 points.
The Tigers got 15 points from Torris Bright and 14 from Antonio Hudson, but the Tigers could not generate enough offense to offset Dupree's lack of output. The junior forward shot 3-for-9 against USC and committed seven turnovers before fouling out of the game with 34 seconds remaining.
"I couldn't get into my rhythm," said Dupree. "I couldn't get the feel for the game the whole night. When I tried to shoot, I was hesitating. It was hard just to get the ball.
"I think (the Gamecocks) were allowed to get away with a lot of things - slapping and grabbing. Then you go to the hole and there's more slapping and grabbing. There's not much you can do."
LSU (14-12, 4-9 SEC) kept within reach of South Carolina through the entire first half and through most of the second, but a 10-2 run from the Gamecocks put the game out of reach. The loss to South Carolina stopped the Tigers' win streak at two games.
For South Carolina (16-10, 6-7), the win over LSU followed a victory at Vanderbilt and marked the first time since December the Gamecocks had strung together two victories.
"I thought South Carolina played extremely well," said LSU coach John Brady. "I thought we guarded well, too. But what I said before the game, we couldn't do. We had to guard Bradley, and we didn't do a good enough job on him and he made some timely baskets."
Trailing 32-31 at halftime, LSU scored the first five points of the second period. But back-to-back three-pointers from Aaron Lucas put USC ahead 38-36 and the Gamecocks did not relinquish the lead the rest of the night.
Lucas finished with ten points as did his teammates, Chuck Eidson and Rolando Howell. The Gamecocks shot 47 percent from the field against LSU and enjoyed a big edge in points off turnovers (29-18) and second chance points (14-4).
"What you saw tonight is we made plays down the stretch that we hadn't been able to make," said South Carolina coach Dave Odom.
LSU got off to a strong shooting start in the first half, hitting 57 percent over the first 20 minutes, but the Tigers converted just 8 of 26 shots (31 percent) in the second half.
Each run the Tigers made at USC was answered with a surge from the Gamecocks. After Bright connected on a three-pointer with 12:32 to play to make the score 44-42, South Carolina answered with a 6-0 run.
The closest LSU came down the stretch was 52-49 with 5:20 remaining on a Dupree layup.
The last chance for the Tigers to contain the Gamecocks came at the 4:13 mark to play when Lucas fouled Bright for the seventh USC team foul. With a chance for LSU to cut into a 55-49 lead, Bright missed the front end of the 1-and-1 opportunity but Brad Bridgewater came up with the offensive rebound and fed to Dupree, who lost the ball driving to the lane. The Gamecocks recovered and Lucas converted the turnover into a three-point shot on the USC end to extend the lead to nine.
Dupree, who scored all six of his points in the second half, connected on a jumper with 3:19 to play to make the score 58-51, but it would be the last field goal in the game for LSU.
"When Ronald Dupree gets six points, we really don't have anywhere else to go," said Brady. "They wouldn't let him catch it, and when he did, he fumbled it several times. We also missed a lot of easy baskets around the goal."
LSU was able to respond to South Carolina's runs in the first half and actually held a four-point lead at one-point in the game.
A pair of Hudson free throws put LSU ahead 9-7 at 15:39, but the Gamecocks outscored LSU 10-2 over the next six minutes to build a six-point lead. Missed shots and turnovers plagued both teams during the stretch, but South Carolina stuck to its trademark defense to deny the Tigers a chance to gain momentum.
"Every time somebody took a shot (and) missed it, they just got back on defense for the next play," said USC center Tony Kitchings. "Usually when we miss, as a team we start to tighten up and we're worried about missing a shot and losing the game. We just went out and played."
The Tigers finally strung together their own run on the strength of two steals from Jermaine Williams that Bright converted into layups on the LSU end. The second made the score 17-15, but Eidson provided a jumper before the media timeout at 7:48 to put USC back ahead by four.
Following the timeout, LSU had a prayed answered when Hudson nailed a three-pointer from close to 30 feet away as the shot clock elapsed to get the Tigers to within a point of the Gamecocks.
Carlos Powell made a free throw with 6:30 to play before halftime, making the score 20-18, and Hudson tied the game 21 seconds later with two from the foul line.
Collis Temple III, who has missed six games this season with leg injuries, saw eight minutes of action in the first half and made his only field goal attempt - a three-pointer that gave LSU a 23-20 lead at the 5:23 mark. He came out of the game shortly afterward having provided the only scoring the Tigers would get from their bench.
The Gamecocks got 27 points from its non-starters.
Howell provided a small dunk off a Dupree turnover to get USC back in front, 24-23, at the 3:50 mark, but LSU scored five unanswered points to post its largest lead of the game, 28-24.
The game of runs continued with South Carolina getting two free throws from Eidson and a Chris Warren three-pointer with 1:43 remaining for a 29-28 USC lead. With 35 seconds on the clock, Hudson drilled a three-pointer to put the Tigers ahead, but the Gamecocks made an offensive rebound on their next possession that allowed Lucas to hit a shot from behind the arc five seconds before the break.
The lead in the game changed hands 15 times, 13 in the first half alone.