Todd Peterson stood on the top step of the dugout, watching a ball soar out of Alex Box Stadium. It landed behind the right-field bleachers, tying the game and eventually putting LSU’s season on the brink of elimination.

Peterson had entered LSU’s first game of the NCAA super regional against Florida State on Saturday after starter Cole Henry left with arm soreness in the second inning. Peterson gave his longest outing of the year, and LSU held a three-run lead.

Two batters after Peterson walked off the field, Florida State tied the game with a home run. The Tigers, plagued by walks, squandered their lead. They lost 6-4, and Sunday night, they must win to extend their season.

“We don't have any time to feel sorry for ourselves,” coach Paul Mainieri said.

Losing Henry forced LSU to scramble. He had shown so much promise during his freshman season, and LSU turned to him with a College World Series berth at stake.

After retiring the side in the first inning on 11 pitches, Henry struggled in the second frame. He walked the leadoff hitter. With two outs, Henry loaded the bases as his fastball velocity dipped from 94 mph to about 92 mph.

Henry struck out Florida State left fielder Tim Becker to strand the bases loaded but needed 30 pitches during the second inning.

Henry walked into the dugout and sat on the bench. Mainieri asked how he felt.

“Not too good,” Henry told Mainieri, and he pointed to his arm.

Henry had missed the final month of the regular season with discomfort in his elbow. MRIs viewed by multiple doctors showed no structural damage. Henry returned to pitch in LSU's opening game of the Southeastern Conference tournament, and last weekend, he threw five shutout innings.

Henry told Mainieri his arm had started bothering him at the end of the first inning.

“There was no decision to be made,” Mainieri said. “He had to come out of the game.”

LSU dipped into its bullpen. Peterson cut through Florida State’s lineup while LSU tacked on runs. The Tigers led 4-0 entering the sixth inning, but the lead felt larger to Mainieri. The Seminoles didn’t have a hit.

After striking out right fielder Reese Albert, Peterson issued his third walk. He gave up a single — Florida State’s first hit — and the Seminoles had runners on the corners. They scored when third baseman Hal Hughes couldn't come up with a high chopper on a play ruled a hit.

Peterson ended the inning against the next batter. He walked off the field pumping his fist, two runners stranded on base.

Peterson began the seventh inning at a season-high 70 pitches. Sophomore Trent Vietmeier warmed in the bullpen. When Peterson allowed a one-out single on his 79th throw, Mainieri signaled for Vietmeier.

Holding the ball, Peterson waited for Vietmeier, meeting his relief a few steps from the edge of the mound. He handed the ball over and pointed at Vietmeier’s chest.

Peterson walked toward a column of teammates who waited to slap his back. Henry stood at the front of the group. He greeted Peterson before anyone else, wrapping him in a hug.

Vietmeier walked the first batter in a full count. Patient Seminoles hitters forced LSU to throw strikes.

Albert came to the plate as the tying run. He and Vietmeier battled into a full count. Albert fouled five straight pitches.

On the 11th pitch of the at-bat, Albert smashed a ball over the right-field bleachers. It crashed into the tile roof of the Marucci Performance Center.

“He finally gave me a pitch I could so some damage with,” Albert said.

LSU used two of its best relievers, Devin Fontenot and Zack Hess, in the eighth, but Florida State took the lead. It walked twice in the eighth and scored on a sacrifice fly. In the top of the ninth, Albert hit another home run.

As LSU began its final at-bat, Peterson stood on the top step of the dugout. He turned his hat backward, waved his arms and clapped. The Tigers put two runners on base, and deafening screams poured onto the field. Peterson motioned for more noise. Antoine Duplantis walked to the plate with two outs.

Duplantis popped up, a harmless ball caught in foul territory by the catcher. Peterson put his arms down. The Tigers walked toward the locker room. Some players sat for a minute, watching Florida State’s celebration.

In the locker room, Mainieri told the players to approach the rest of the series one game at a time. If they win on Sunday, they force a deciding Game 3 on Monday. They have showed resiliency throughout the season. They must do so again.

"If we win tomorrow," Mainieri said, "we shift the pressure onto them."

An hour after the game, one LSU player leaned against the dugout railing. Dressed in street clothes, the brim of his hat covered his face. Staff cleaned the stadium for Sunday’s game. The player stared at the field for a couple minutes, then he walked inside, one game left to extend LSU’s season.

Follow Wilson Alexander on Twitter, @whalexander_.