The win snapped a three-game losing streak for the Tigers, who improved to 4-7 this season. The visiting Spartans fell to 2-9.
"The turkey is going to taste better on Christmas," a smiling Auburn coach Tony Barbee said after the victory and sending his players home for a holiday break.
The reason that happened was on the defensive end of the floor, the coach said.
Auburn limited USC-Upstate to 36.2 percent shooting while the Tigers made 46.3 percent of their shots, including 55.6 percent of their field goals in the second half.
"We didn't do anything different (offensively) in the second half," Barbee said. "What happened is we fed off what we did defensively. We hit some early threes in transition and some post-ups in transition. We have trouble producing shots in the halfcourt because of what we are offensively."
The game was the third one this season for junior guard Frankie Sullivan, who agreed with his coach on the winning formula.
"Defense is going to be our motor right now," said Sullivan, who had five of Auburn's eight steals. "I know from experience that playing defense and making free throws wins championships."
Frankie Sullivan is fouled in Tuesday night's game.
The Tigers, who have been up and down as a free throw shooting team, hit 74.2 percent of their chances at the foul line making 23-31. That was a huge difference in the game as the Spartans made just 3-8 free throws.
The Tigers held a slight edge in rebounding, 34-31, and had 11 turnovers, one fewer than the Spartans.
While happy with the win, Barbee said he continues to be concerned with his team's rebounding.
"I struggle because I am a man-to-man coach," Barbee said. "I want to guard man-to-man. I have just got to come to the realization that we can't guard man-to-man. The zone looked good tonight. We just have to learn how to rebound better. So many of those balls we get in our hands we can't hold on to them."
The coach had high praise for Sullivan's play as the guard has contributed despite being far less than full speed after having ACL surgery in July. Sullivan made his first start of the season and finished with 14 points, six assists and no turnovers while hitting 3-8 field goals in 28 minutes.
"He has a very high basketball IQ that gives us a spark," Barbee said. "All that he brings to the floor is going to go a long way towards helping this team grow because he does it every day in practice. That is why he is back so soon because he did it every day in rehab."
Barbee said he hopes the team can learn to play with Sullivan's toughness.
Sullivan is the only returning starter from last season. "It really doesn't matter to me if I start or come off the bench," he said. "I just want to contribute and help the team get a win and that is what we did tonight."
Sullivan said he still needs to work on his conditioning so he won't get as tired as he did on Tuesday night. He said that is something he will concentrate on while going home for the Christmas break.
Earnest Ross led the Tigers in scoring with 16 points. He was 6-6 at the foul line and made 4-8 field goals. He added six rebounds in 24 minutes.
Ross said he will head into his break in a better frame of mind following a much-needed victory. "Now you go into the break not worrying that Coach is going to run you to death when you get back," he said with a smile.
Auburn led just 29-26 at halftime before outscoring the Spartans by 11 in the second half. Auburn led 39-38 midway through the second half, but took control with an 11-0 run. Asked why that happened, Ross said, "We defended. Defense was the main part of this win."
Tony Dukes led the Spartans with 13 points as he hit four of his team's nine treys on 17 attempts. Auburn hit 7-18 threes.
The Tigers will return to action on Dec. 29th with a home game vs. Georgia Southern at 7 p.m.