In the seventh inning of a tie game, Michael Papierski went to the plate hunting for a fastball, and he got one.

He sent a 1-0 pitch from Auburn ace Keegan Thompson high into the night air, and finally into the right field bleachers, to swing the momentum and series in LSU’s favor.

“You try to get ahead in the count — 2-0, 3-1 — you’ve got to bank on a fastball coming,” Papierski said. “… You’ve got to hit the fastball.”

Papierski’s two-run blast in the seventh inning gave LSU a 5-3 lead that it would not relinquish, and it clinched a series win against Auburn, keeping the home Tigers right in the thick of the conference title race.

It was the sixth consecutive loss for Auburn (32-20, 14-12 Southeastern Conference), which was in first place in the SEC before its losing skid.

Auburn tied the game in the top half of the seventh, and it was bringing Thompson out to start the bottom half at only 71 pitches. LSU had mostly struggled to figure Thompson out at that point, managing only four base runners in the first six innings.

But Thompson walked LSU third baseman Josh Smith to start the inning — only his second walk of the evening — and Papierski made him pay for the mistake.

“They’d just tied it up,” Papierski said. “Some teams are going to hang their heads, but we came in and everyone said, ‘Alright, now it’s time to go, it’s 0-0. Are we going to win in three innings?’ ”

When Papierksi crossed the plate, he did so in the middle of a raucous celebration started by his teammates. Papierski only added to the intensity, sending teammate Greg Deichmann stumbling backward after the two jumped into each other to bump chests near the LSU dugout.

The LSU catcher, hitting .197 on April 14, has gone 12-39 (.308) with a couple game-winning hits since reaching that low point. Like he did last season, he’s playing his best at the right time of year.

“If Pap keeps getting hot, which he did at the end of last year going into the postseason, I think that will help our offense an awful lot,” said LSU coach Paul Mainieri.

With the lead established, Zack Hess (6-1) and Hunter Newman combined to keep Auburn off the scoreboard in the eighth and ninth innings to preserve the win. Newman earned his eighth save of the season.

Papierski gave LSU (34-17, 17-9) a lift when it needed it most.

LSU starter Jared Poché left the mound with a 3-1 lead and two outs in the seventh inning. In what may have been his last appearance at Alex Box Stadium, an appreciative crowd sent him to the dugout on the heels of a roar as his teammates gave him hugs.

“Those standing ovations never get old, man,” Poché said.

That feel-good moment evaporated quickly, though.

Hess entered in place of Poché and got No. 9 hitter Will Holland to ground to third base, but Smith skipped the throw to first base and it got away from first baseman Nick Coomes, rolling into foul territory and allowing Hess’ inherited runner to score.

Holland wheeled to third base, then scored and tie the game on Jonah Todd’s sharp single to right field.

It ruined an otherwise storybook day for Poché, who graduated at Alex Box Stadium Friday morning, then twirled a gem Friday night.

With Thompson putting together an impressive game in his own right opposite him, Poché put LSU in position to win with 6.2 strong innings.

“Just like he always does, Poché met the challenge,” Mainieri said.

He was staked to a lead by the bottom of LSU’s order.

Papierski — batting in the No. 8 spot — started the first scoring rally when he drew a one-out walk, took third on Zach Watson’s sharp liner that glanced off third baseman Josh Anthony’s glove, then scored on Kramer Robertson’s high chopper over the mound.

LSU added to that lead on Watson’s two-run, no-doubt home run to left field in the bottom of the fifth that made it 3-0. Unlike Papierski, Watson went to the plate looking for a curveball. Like Papierski, he drilled the pitch he was looking for.

“We’ve settled down in the clutch,” Watson said. “We’re not pressing as much. We’re getting the job done now, and that’s what matters.”

LSU will face a stiff challenge as it goes for the sweep Saturday, as Auburn will send dynamic right-hander Casey Mize to the mound. LSU will counter with freshman right-hander Eric Walker.

Follow Luke Johnson on Twitter, @ByLukeJohnson.