Because it was Senior Day, DaShawn Harden got her first start in a month and a half.

Man, did she know how to finish.

Her LSU women’s basketball team facing a crucial regular season-ending game Sunday against Texas A&M, Harden put the Lady Tigers on her slender shoulders and set them on course quickly for a dominant 80-63 victory over the No. 12 Aggies before 2,315 at the Pete Maravich Assembly Center.

Harden gathered in the opening tip and flitted to the LSU basket for a score. With 18:22 left in the first half she buried the first of a career-high five 3-pointers.

Seconds later, she stole a pass and drove for another layup, putting the Lady Tigers ahead 9-2 with 18:08 left.

Harden didn’t stop. She added four more 3-pointers, and three free throws when she was fouled attempting a 3-pointer by Courtney Williams, giving her 22 in the first half.

It wasn’t until the 6:19 mark of the first half when Williams answered with a 3-pointer of her own that A&M outscored Harden 19-16. By that point, LSU was still up 34-19, on its way to a 47-35 halftime lead.

The Aggies would never get closer than 10 points after that. Harden finished with a career-high 28 points.

“It’s nice,” Harden said, the definition of understatement. “I wasn’t expecting that. I was thinking I’d get defensive stops, that was my main focus, (Raigyne Moncrief), Danielle (Ballard), Rina (Hill), they kept finding me. You can’t make shots without people passing it to you.”

After two straight road losses to Arkansas (63-41) and Ole Miss (58-57), LSU passed A&M and Kentucky to secure the No. 4 seed in this week’s Southeastern Conference tournament.

LSU (16-12, 10-6) will get a double-bye all the way into the quarterfinal round Friday in North Little Rock, Arkansas. The Lady Tigers will play No. 5 seed A&M (22-8, 10-6), No. 12 seed Florida (13-16, 5-11) or No. 13 seed Auburn (12-17, 3-13) at about 2:30 p.m.

Given their recent road swoon and 6-6 nonconference start, the win was a big bold check mark on LSU’s flagging NCAA tournament résumé.

The Lady Tigers came into Sunday with a No. 79 RPI. But now that they have 10 wins (three over current top-50 opponents; A&M was No. 24) and a top four-seed, they have some weighty history on their side.

Since the NCAA women’s tournament expanded to 64 teams in 1994, only one team that earned a top-four SEC tournament seed failed to earn an NCAA bid. And since the SEC went to a 16-game regular-season women’s schedule in 2010, all 22 teams with 10 or more SEC wins made the NCAA tournament.

“A lot of teams could play 16 games in our conference and not get 10 wins,” LSU coach Nikki Caldwell said. “But we’re one of those this year.”

Texas A&M coach Gary Blair gave LSU his vote.

“Hopefully this win will definitely put LSU in there,” he said. “They need to be.”

Blair’s Aggies suffered a crucial defeat Thursday, a 70-69 home loss to Missouri when point guard Jordan Jones went down with a season-ending knee injury.

A&M seemed to have trouble much of the game getting into its offense. LSU made it worse with a full-court press that resulted in 11 steals and led to 24 Aggies turnovers.

Blair refused to use Jones’ injury as an excuse, crediting LSU’s energy and sense of urgency along with Harden’s play.

“Harden played like a senior should play,”he said. “She has taken the back seat to Moncrief and Ballard for too long. She can play; she’s a threat.”

The former junior-college transfer from Olathe, Kansas, went to the bench not long after Ballard returned from a 14-game suspension to start the season. On Sunday, she started for the first time since Jan. 18 along with fellow senior Sheila Boykin, a regular starter and Caldwell’s first four-year player at LSU.

“We’ve got unbelievable seniors,” Caldwell said, “and it was very special to send them out on a good note as far as our regular season is concerned.”

Ballard added 20 points, 12 in the second half, and a team-high seven rebounds, while Moncrief had 10 points. Boykin finished with four points and six rebounds.

Williams led Texas A&M with 19 points while Courtney Walker added 12 and Khaalia Hillsman 10.

Tori Scott, a senior from John Ehret High School, added five points in front of her very own rooting section behind the A&M bench.

Follow Scott Rabalais on Twitter: @RabalaisAdv.