Freshman guard DeWanna Bonner led the charge for Auburn with career high of 25 points and 13 rebounds vs. the now 17-11 Gamecocks. It was her fifth double-double this season.
Bonner hit 9-18 field goals and had two offensive and 11 defensive rebounds.
Auburn jumped on the higher seeded team early by scoring the game's first 13 points and never trailed.
USC cut the lead to 27-21 by halftime, but Auburn regained the momentum in the second half and was never seriously threatened.
"It was an outstanding effort on our team today," Auburn coach Nell Fortner said. "The difference in the game was having Whitney Boddie on the floor as opposed to the last time we played South Carolina and she is a difference maker."
DeWanna Bonner scores vs. South Carolina.
Boddie, a freshman point guard, did not play in the regular season meeting with USC because she was suspended. In the rematch she contributed 10 points, six assists, five rebounds and three steals.
Another freshman, center Keke Carrier, added 10 points and six rebounds. Auburn also got 10 points from senior guard Nitasha Brown.
Auburn scored the first nine points of the second half to build a 15-point lead and took the lead to as many as 21 points.
Auburn shot 43.1 percent from the field and held the losers to 29.2 percent shooting.
Auburn made just 1-7 threes while USC was 2-6.
Auburn was 13-18 on foul shots while USC made just 4-11.
The Tigers out-rebounded USC 44-43 and had 13 turnovers, one more than the losers.
South Carolina is considered an NCAA tourney "bubble team" and the loss to the Tigers could knock the team out of the event. Melanie Johnson led USC with 14 points and 11 rebounds, but no teammate scored in double figures.