Five Auburn players scored in double figures led by 21 points from senior guard DeWayne Reed to overcome an impressive performance by senior Tasmin Mitchell who scored 38 points for LSU.
Auburn, which improved to 10-9 overall and 1-3 in the SEC, got 15 points from sophomore guard Frankie Sullivan. He hit a key three-pointer from the wing with 1:10 left in the game to put the visitors ahead for good at 78-76.
Sullivan made 4-5 field goals, 3-4 threes and 4-4 foul shots while adding three assists and two steals with no turnovers.
With 27 seconds left Sullivan hit a pair of free throws to stretch Auburn's lead to 81-76 to give the Tigers control of the game.
"Frankie Sullivan was terrific tonight," Auburn coach Jeff Lebo said. "He made the big shot at the end. He is not afraid to take a big one."
Brendon Knox came off the bench to contribute 10 points, six rebounds and three assists for Lebo's Tigers.
Mitchell put on a show for the home folks. The LSU senior hit 15-22 field goals, 4-7 threes, 4-5 free throws and added 10 rebounds. Auburn wasn't able to stop him until late in the game when Lebo gave freshman Earnest Ross the defensive assignment.
"His first half, we could not stop him," Lebo said of Mitchell. "He was getting his shot off so quick and we just didn't do a very good job of getting to his shot."
Lebo said that the game plan was to force Mitchell to shoot from outside because he is such a good offensive rebounder, but noted that wasn't working. "When he was making them like that we needed to pressure him a little bit more. Finally we found somebody (Ross) who could guard him."
LSU, the defending SEC champion, slipped to 9-9 for the season and 0-4 in the league.
Auburn shot 52 percent from the field making 26-50 field goals. The Tigers were 10-22 from three-point range and they hit 22-33 free throws.
LSU hit 28-63 field goals to finish at 44.4 percent. The Bayou Bengals made 5-18 threes and 19-24 foul shots.
LSU won the rebounding battle 37-28 and each team turned the ball over 11 times.
Lebo said one of the keys to victory was the play of redshirt freshman point guard Josh Wallace, who played 13 minutes in the first half when Reed got into early foul trouble. "Josh did a great job, scored a couple of buckets for us and really ran the team well and kept us in the game."
LSU scored the first six points before Johnnie Lett scored for Auburn.
Lebo's team took its first lead at the 15:49 mark on a basket by Brendon Knox and led much of the half. Auburn's biggest lead came at the 8:42 mark after Lucas Hargrove hit a pair of free throws to put his team up 27-18.
However, Auburn couldn't control Mitchell who led a comeback that put LSU?up 47-45 at intermission.
LSU built the lead to 60-53 with 13:38, but Auburn pulled ahead at 61-61 after a pair of back-to-back threes by Reed. LSU regained the lead and moved ahead by four points, but couldn't shake the visitors who cut the lead to 76-75 with 1:47 to play on a fastbreak basket after a steal by Sullivan and Ross.
That set up Sullivan's go-ahead three and Auburn then hit five of six free throws in the closing seconds to preserve the lead.
"I think everybody really contributed in this game," Lebo said. "Frankie's big shot was certainly key and he made some big plays. Some other guys made some key contributions when we couldn't guard Mitchell obviously. We put Earnest finally on him, and he came in and did an excellent job and didn't give him many touches and looks. Mitchell was terrific tonight shooting the ball.
"A key offensive rebound on the free throw by Earnest gave us an extra possession," Lebo added. "It really helped us seal the game at the end. We played most of the first half with Reed on the bench and a walk-on freshman point guard on the road in the league and felt pretty good going in at halftime just down two."
Auburn returns to action on Saturday at Vanderbilt. Tipoff is 12:30 p.m. CST from Nashville.