AUBURN, Ala. — Bad things are supposed to come in threes.

For the LSU men’s basketball team, good things came in threes Tuesday night, at a crucial point in a must-win Southeastern Conference matchup with Auburn.

On six trips down the floor early in the second half, LSU scored 15 unanswered points on three 3-pointers in a row and two old-fashioned three-point plays that helped spark a 84-61 victory over Auburn at Auburn Arena.

Nineteen days after dropping an 81-77 decision to Auburn on its home floor, LSU turned the tables in a big way with two things that were sorely missing in their first meeting: aggressiveness on offense and sticky perimeter defense.

LSU (20-8, 9-6) picked up a win it simply had to have after the earlier setback to Auburn (12-16, 4-11) with that 15-0 run after a nine-point lead early in the second half was trimmed to just 49-46 with 15:47 left.

The victory enhanced LSU’s NCAA tournament résumé and clinched a second consecutive 20-win season for the Tigers, helping coach Johnny Jones become the first men’s basketball coach in school history to win 20 games twice in his first three seasons.

“I knew how important it was for us to get this victory after they came in and beat us at home,” said forward Jarell Martin, who scored 25 points and had 12 rebounds. “I definitely wanted to come in and get the victory. It feels good.”

While LSU produced its best shooting night of the season in hitting 57.8 percent of its shots, going 37-of-64, the bigger story was the defensive job it did against Auburn’s top two scorers: guards KT Harrell and Antoine Mason. Guards Tim Quarterman, Keith Hornsby, Jalyn Patterson and Josh Gray held Harrell and Mason to a combined 20 points after they scorched LSU for 52 in a stunning upset Feb. 5.

Harrell, who leads the SEC in scoring at 17.9 points per game, had 14 points; Mason, who averages 15.6, had just six — all on free throws. Harrell poured in 28 points and Mason added 24 in the earlier matchup.

Quarterman was matched up with Harrell, and Hornsby took Mason from the outset. Their play on the defense helped LSU to a 30-22 lead before Harrell got his first points with 4:56 to play in the first half.

“At the last game, there was a lot of criticism on our guards because all three of their guards, their big-time scorers, went off that game,” Quarterman said. “So I just took it to heart and wanted to come out here and tried to lock it down.”

The key to that, he said, was fighting through screens and making sure Harrell didn’t get off to a good start.

“I wanted to play physical with him, make sure he didn’t get off early and I wanted to stay in his wheelhouse,” Quarterman said. “I had to go over every screen, and I just had to stay attached to him and make sure I didn’t lose him.”

Harrell made 5 of 11 field-goal attempts, but Mason was 0-of-5. Harrell was 2-of-6 on 3-pointers after those two dropped in eight of Auburn’s nine 3s in the earlier game. On Tuesday, Auburn was just 7-of-25 on 3s en route to shooting just 37.7 percent from the floor.

“I thought Tim’s initial defense was great for us, and at the same time we have to credit the whole team,” Jones said. “We did not do a great job at home against (Auburn). They blistered us at home in terms of making 3s. We did a great job crowding them (at the 3-point line). We wanted to make sure we did a great job of staying attached. Tim initiated that, and our other guys did a great job of helping him. It certainly took a team effort to try and hold those guys down.”

“Obviously, we had their first performances in our minds when we set foot on the floor tonight,” Hornsby said. “We knew (Mason) had just come off a game where he almost had 30 at Kentucky (actually 29), so we figured he was going to come out gunning. Of course, that was a big part of our scouting report and a goal for the game was to shut those two down.”

While the defense was a key, the offense also came up big — especially when Auburn got hot in the second half. But after Auburn got within three points, LSU broke its backs with three straight 3-pointers from Patterson, Martin and Hornsby.

Then Martin hit two baskets down low and made both free throws to extend the lead to 64-46 with 12:34 remaining.

In addition to Martin’s 25 points, Patterson notched career highs with 16 points and seven assists, Mickey had 14 points and three blocks — giving him 101 for the season — and Hornsby had 13 for his 11th consecutive game double-digit game.

With the offense to go with the defense, the payback was complete.

“We watched highlights of them talking and everything and saw some emotional plays,” Martin said of the first game. “We wanted to come out and do the same, come out here and battle and cheer at the end of the game.”

Follow Sheldon Mickles on Twitter @MicklesAdvocate.