Fifty-six minutes of LSU’s 4-2 regional win against Rice were needed for Paul Mainieri to make a decision that agonizes him the most.

Mainieri’s a staunch protector of the many prized arms he and pitching coach Alan Dunn groom. Rarely does the desire to win a baseball game outlast the duo’s duty to ensure these men leave their program ready for what lies ahead.

Alex Lange had 72 pitches, the last of which found the warning track in left-center field for Ford Proctor’s RBI double. The deficit was 4-2 as rain deluged from the sky, necessitating another tarp pull in a regional that’s already endured too many. Lange stewed in the dugout with six strikeouts on his line.

Mainieri and Dunn met. Dunn suggested if the delay was “between 45 minutes and an hour,” they could send Lange back.

“Obviously, my biggest concern is always to do what’s right for Alex and his health and his career,” Mainieri said. “He was staying loose during the break. We had him back in the trainer’s room, doing all kinds of exercises and we and extra time to get his arm ready. I felt very confident and comfortable sending him back out there.”

Mainieri often says Jared Poche, not Lange, is more suitable to return after such a delay. Lange taxes his body with his power repertoire, pumping fastballs in the mid-90s to accompany the spiked breaking ball Wayne Graham called “the best Rice had seen all year.”

Lange emerged following the delay, towel on his shoulder and catcher Mike Papierski at his side. The two played long toss in the bullpen, Mainieri and Dunn’s keen eyes watching each throw.

“I was pretty locked in,” Lange said.”It was never even really a question to come out. We knew it was going to be a quick delay. It sucks that it happened, but you have to stay locked in.”

The reigning National Freshman of the Year returned, retiring the go-ahead run twice in the sixth inning, putting his team in the regional’s drivers seat.

Four of Lange’s 10 strikeouts came in the 2.2 innings Lange pitched following the delay. His eight-inning outing was masterful, the only blemishes a towering solo home run to Grayson Lewis in the fifth and Proctor’s RBI double prior to the delay.

The 56-minute pause did nothing to disrupt his assault on a Rice lineup that features just four hitters over .300. His velocity held at 92 mph, according to the stadium radar gun. He mixed in an 86 mph changeup while, obviously, landing the curveball that leads his arsenal.

“It was the same as he was the first five innings,” Papierski said. “Started with a breaking ball for a strike and it was off and running from there.”

Proctor, the Conference USA Freshman of the Year, watched one fall at his knees in the eighth for Lange’s tenth strikeout. His gem ended after Connor Tekyl’s leadoff single dropped just in front of Antoine Duplantis in the ninth.

Hunter Newman got the final three outs for his seventh save.

The win made LSU 2-0 for the 18th time in 24 NCAA regionals at home. Of those 18 times, the only time the Tigers failed to advance to a super regional or the College World Series was in 2014 against Houston.

The 11th postseason meeting between the nearby teams was billed a pitcher’s duel. Opposing Lange was Jon Duplantier, the Conference USA Pitcher of the Year.

Like his counterpart, Duplantier has three pitches. He commanded none of them, walking three of the first four batters he faced to load the bases. Six Tigers reached via walk in the first four innings and another, Beau Jordan, was plunked in a full count.

“I just lost myself,” a stunned, nearly speechless Duplantier said. “Just completely lost myself.”

Duplantier’s three walks loaded the bases in the first inning. Greg Deichmann turned on a two-strike fastball down the first-base line, where it came to rest under the bullpen bench. Owls right fielder Charlie Warren attempted to grab it before raising his arms toward the umpires to signal it unplayable.

The Alex Box Stadium ground rule reads: “If the ball goes under the bullpen bench and remains under the bench, the ball is dead ... unless the defensive player goes in to retrieve it. A ball that goes under the bench and comes out remains alive.”

Umpires awarded Deichmann a two-RBI, ground-rule double as he crossed home plate. He raised his hands into the air, befuddled at the ruling after adhering to the rules under which he’d played an entire home season. Paul Mainieri joined him in incredulity, jogging nearly to the outfield while gesticulating for a grand slam.

A brief conversation with his three co-workers left first-base umpire Harry Greer circling his finger in agreement. The dugout spilled in appreciation of baseball’s rarest feat — an inside-the-park grand slam — as Graham slowly walked to receive the same explanation he heard during the coaches pregame meeting at the plate.

Chris Reid smoked a single the opposite way two batters later, the fifth batter to reach safely against Duplantier.

Five innings passed before another Tiger hit safely, the futility erased on Mike Papierski’s ringing, two-out double down the right field line off Glenn Otto — Rice’s First Team All-Conference USA closer. Papierski had two hits. The rest of his team had four.

Tigers third base coach Nolan Cain waved Brennan Breaux, inserted as a pinch-runner at first base moments earlier. Dayne Wunderlich and Proctor produced a perfect relay, nabbing the LSU freshman sliding into home. An important insurance run was gone.

Lange did not require it.

“I’ve run out of superlatives to say about him,” Mainieri said of his right-hander. “He’s just an amazing competitor. There’s something that makes him different from other pitchers, that’s his competitive zeal. He just has the ability to rise up and make a big pitch when he needs it in clutch situations.”

Follow Chandler Rome on Twitter, @Chandler_Rome