It was the first SEC road victory for first-year head Auburn head coach Jeff Lebo, whose team improved to 12-11 overall and 3-7 in the conference.
The Gamecocks, who were 11-1 on their homecourt this season, fell to 13-8 overall and 5-5 in the SEC.
The Tigers shot 48.1 percent overall from the field to 42.6 percent for the home team, which struggled from three-point range, hitting just 4-16 attempts.
Ian Young led the Tigers with 23 points. He hit eight of 12 field goals and two of four of his free throws. He drilled five three-pointers on nine tries.
Freshman guard Toney Douglas scored 19 for the winners. He was 6-12 from the field, 3-5 on three pointers and 4-5 at the foul line. As a team, Auburn was 13-19 at the foul line while USC hit 9-14 free throws.
Brown, who scored 19 points and pulled down 13 rebounds for the Tigers, did a good job defending South Carolina's leading scorer, Carlos Powell, who finished with 14 points. "Statistically, someone who looks at the paper will say that Carlos did a good job, but anyone who saw the game knows he didn't have one of his best games and that is too bad," Odom said. "In order for us to win he has to play well every night."
Josh Gonner, a 6-3 sophomore guard who was averaging 8.1 points per game, led the Gamecocks with 22 points. He hit four three-pointers and was the only USC player to make a trey.
Auburn played the game without starting guard Frank Tolbert, who was held out of action due to a concussion. Auburn used just seven players with Daniel Hayles moving into the starting lineup and walk-on guard Moses Edun and football player Kyle Derozan, a post player, coming off the bench.
"In the second half when we needed baskets, I thought we were patient offensively to get a good shot," Auburn coach Jeff Lebo said. "We didn't take quick ones. In this game, other than one time, I don't remember us taking a bad shot."
Auburn started well, jumping to a quick 5-0 lead on a three-pointer by Douglas and a basket by Young. Auburn's biggest lead of the first half was at 13-7 on another three-pointer by Douglas.
The Gamecocks then responded with an 8-0 run to take the lead. The teams swapped the lead the rest of the half. USC's largest margin of the first half was four points at 28-24. At intermission the game was tied at 33-33.
The Tigers came out smoking after the break. Douglas hit a three-pointer and Brown scored inside and drilled a pair of three-pointers as the Tigers stretched their lead to nine at 44-35.
The Tigers pushed their margin to double figures at the 16:43 mark with a pair of free throws by Douglas to make the score 46-35.
Auburn extended its lead to 13 at 53-40 on a three-pointer by Young. The Tigers built the lead to 14 at 60-46 on another three-pointer by the senior guard.
The home team then went on an 8-0 run to cut the Auburn lead to six points before Daniel Hayles scored his first basket of the game with 4:36 left to make the lead 62-54.
The Gamecocks cut the lead to 64-59 at the 2:40 mark on a basket by 6-3 guard Josh Gonner. At the 1:55 mark, Gonner hit a three-pointer to cut the lead to 64-62.
However, the Tigers responded to the challenge with a three-pointer by Nathan Watson and a free throw by Hayles to stretch the margin to 68-62 with 59 seconds left.
Baskets by Powell and Gonner following a pair of Auburn turnovers cut the lead to 70-68 when Young hit a pair of clutch free throws with 25.4 seconds left to increase the lead to four points.
However, the Gamecocks couldn't score on their next possession and Watson hit a basket to ice the game. A three-point buzzer beater by Gonner cut the final margin to 74-71.
"I thought we were very efficient from the three-point line," said Lebo, whose team was blown out 90-69 in a road loss on Wednesday at LSU when the threes weren't going down. "We made the extra pass and got maybe a little bit higher quality shot in this game."
Auburn turned the ball over 13 times against South Carolina's pressure defense and AU caused 10 USC turnovers. Auburn was out-rebounded 42-31 in the game by a team with four starters taller than AU's tallest player who saw action.
The Tigers managed to win the game watched by a crowd of 13,313 with just one point from the bench--a free throw by Derozan, who played for seven minutes. Edun played for 16 minutes and didn't score or have a rebound.
Douglas, Young and Watson played the entire game without a break. Watson scored nine points and added seven rebounds.