LSU won its first four games of the season with relative ease, but nothing came easily for the third-ranked Tigers against BYU on Thursday night in Alex Box Stadium.

Aaron Nola had a subpar game as LSU faced its first-multi-run deficit of the season, and the Tigers went into the ninth inning trailing by a run. But Christian Ibarra’s home run tied the score, and Raph Rhymes’ bases-loaded RBI single broke that tie as the Tigers escaped with a 6-5 victory.

“It was good to win a game like this,” Rhymes said. “A lot of young guys hadn’t experienced that yet.”

One of them was Ibarra, a junior-college transfer who lined a fastball from Cougars closer Matt Milke (0-1) into the gusty wind and over the fence in left.

“I went into the at-bat taking an aggressive approach,” Ibarra said. “He threw a fastball high and inside that was hanging up around my head. At first, I thought it was a pop fly, then I thought about the wind. And when I saw it carry, I was pretty pumped.”

Chris Sciambra followed with a walk, and Mark Laird, a freshman who was 2-for-15 coming in, lined a single to left for his fourth hit of the game as Sciambra stopped at second.

“Over the course of the first few games, I’ve been trying to settle in,” Laird said. “I felt like I had more confidence at the plate. I was selective on the pitches I swung at and tried to get a good pitch and get the best opportunity to get myself on base.”

Alex Bregman followed with a line-drive single to right, but it was hit too hard for Sciambra to score. That brought up Rhymes with the bases loaded and one out.

Rhymes, who was 0-for-3 with a walk, took a ball, then hit a fly to deep left. Sciambra tagged and would have scored easily on a sacrifice fly, but Rhymes got an RBI single when left fielder Jacob Hannemann overran the ball as the wind got a hold of it.

“I had struggled in my previous at-bats,” Rhymes said. “I did have sacrifice fly in the back of my mind, but I was really just trying to hit the ball hard.”

When Sciambra crossed the plate, the home dugout emptied and Rhymes’ teammates mobbed him between first and second base.

The Cougars (2-3) will play Southeastern Louisiana at 1 p.m. Friday at the Box, and SLU and LSU (5-0) will play at 7.

Joey Bourgeois (1-0), the fourth LSU pitcher, threw 12?3 scoreless innings after BYU had taken a 5-4 lead in the eighth.

Nola (1-1) gave up six hits and four runs and walked a career-high three in six innings.

“I didn’t have my ‘A’ game,” Nola said. “I had three walks, and that’s going to hurt me no matter what. I went as long as I could. My pitch count was up (at 90).”

Hayden Nielsen led off the top of the eighth against Will LaMarche, who relieved Nola and threw a perfect seventh, and beat out an infield single. After Adam Law lined to left, Hunter Devall relieved and Jaycob Brugman ripped an RBI double into left-center to give BYU the lead.

LSU took a 1-0 lead in the second when Mason Katz hit his first home run of the season into the left-field bleachers.

BYU battered Nola in the third. Hannemann walked with one out, Nielsen singled him to third, and Law’s single tied the score. Brugman followed with a long home run to right-center to give the Cougars a 4-1 lead.

“I missed one of my spots in a crucial situation, and the guy made me pay for it,” Nola said. “It was a game-changing home run, but luckily our hitters came back and battled their way through the game and we got the walk-off.”

Laird led off the bottom half with a wind-blown double that Hannemann overran.

One out later, Rhymes walked and, with two outs, JaCoby Jones lined a 3-2 pitch into right-center for a double that scored both runners and made it 4-3.

LSU scratched out the tying run against reliever Derek Speigner in the seventh. After two were out, Laird chopped a single into left field.

Bregman followed with a high pop to medium right. The ball dropped just in front of right fielder Kelton Caldwell and barely in fair territory as Laird scored.

“You take these types of wins, and they continue to build the confidence of the team,” Tigers coach Paul Mainieri said. “I don’t think we played our best game, but we found a way to win, and that was what was important.

“We have a different hero every day. If you want to be a championship team, you have to win games like this sometimes.”