At the end of a tunnel in the the Pete Maravich Assembly Center, Shirley Gaspard keeps quiet watch over the entrance to LSU locker room.

With a book in hand Tuesday, though, a surprise guest slipped into the arena.

She wore aviator sunglasses to block out the light, black sweatpants and a gray longsleeve T-shirt as she greeted Gaspard.

Two minutes remained in the sixth-seeded Lady Tigers 71-66 upset of No. 3 seed Penn State, sending the program to its first Sweet 16 since 2008 and a meeting with No. 2 seed California.

The teams square off at 10:32 p.m. Saturday.

After after a collision Saturday with guard Adrienne Webb, a concussion couldn’t keep guard Jeanne Kenney away from the building.

“She totally surprised me when she came in,” said Gaspard, who has worked the same spot for eight years. “She said she couldn’t stay away.”

Waiting outside the LSU training room, a surprised Webb wrapped Kenney in a hug after notching a career-high 29 points on 10-of-16 shooting, including a go-ahead 3-pointer from the top of the arc with roughly three minutes left.

“That one was for you, baby!” Webb screamed.

Two days removed from serving as the catalyst early in the second half against Green Bay, Webb reprised the role.

In her final home game, the 5-9 senior reeled off six consecutive points as LSU reeled off a 10-0 run to take a 45-42 lead with 16:11 left to play.

“We just came out on fire and started feeding her the ball,” forward Theresa Plaisance said, referring to Webb. “She just couldn’t miss. She was as hot as pistol, so we just kept going back to her.”

And the setup didn’t change much, either.

The Lady Tigers worked Webb off stagger-screens for two jumpers off the left wing and a pick-and-roll layup with Plaisance near the left elbow.

“They couldn’t hold her,” freshman guard Danielle Ballard said. “They could handle screens, and they couldn’t handle Webb off the dribble.

“We attacked that.”

Curling off two of them set near the top of the key, Webb pump-faked and stepped around Nittany Lions guard Alex Bentley for a go-ahead jumper near the left baseline.

“I do like coming off screens, curling to the basket, getting my midrange game going,” Webb said. “It really came through tonight.”

And she bookended the second-half — one where LSU endured a 6:11 scoreless stretch to fall behind 60-58 and 6:10 left — to lift the Tigers to a trip to Spokane, Wash.

With Lutley trapped in a triple-team underneath the rim, the fellow senior spied Webb at the top of the arc and fired an overhead pass to beat a close out from Penn State guard Maggie Lucas.

“No hesitation,” Webb said of her decision to loft a 3-pointer. “That’s a shot I’ve knocked down so many times. It’s automatic.”

Twine rippled. The 3,055 fans in the lower bowl bellowed. And Penn State, rolling out a 10-player rotation, realized the pendulum had swung in favor of the Lady Tigers.

“A big boost of momentum,” said Penn State coach Coquese Washington said softly afterward.

Meanwhile, LSU clamped down in the waning minutes. The Nittany Lions knocked down just 2 of 9 shots to close out the game’s final six minutes and didn’t score again after Nikki Greene’s lay-up with 54 seconds left for a 66-65 lead.

“What’s inside of you?” said Webb, repeating the team’s chief thought.

Only Lutley answered, splitting a double-team in the lane to watch a floater fall with 40.9 seconds remaining to put LSU ahead for good 67-66.

But it was Webb that strode the floor with 20.9 seconds to go for a pair of free throws after LSU secured a rebound when Bentley’s errant 3-pointer hit off the backboard.

Calmly, Webb swished them through.

But a prologue was necessary, too.

Greene’s desperate pass underneath the rim was popped up with 4 seconds left, landing in Webb’s arms near the half court, where she was fouled by Ariel Edwards.

Peering down the concrete corridor, though, Kenney ducked around a corner into the confines of the training room as Webb salted away the victory.

Webb appreciated the surprise.

“All I’m thinking is, ‘I’m glad she’s here,’ ” Webb said.