BATON ROUGE — One pitch in the top of the fourth inning provided Houston the only offense necessary to successfully navigate UL Lafayette — and a four-hour weather delay — on Friday in LSU’s Tiger Park.

Arielle James’ leadoff shot to left field marked the only run of NCAA’s Baton Rouge Regional opener to help teammate Savannah Heebner get the better end of the pitcher’s duel with the 1-0 victory.

“I was really excited,” James said. “When I went in, I was just looking for a base hit, and it ended up being a home run. It was really exciting — my first hit of the tournament, first hit of the regionals.”

Lightning and rain struck during the top of the second inning of the still-scoreless contest and kept the Cougars (37-20) and Ragin’ Cajuns (38-15) off the field for four hours and 19 minutes.

Even then, UL could never get going offensively.

“We knew it was going to be a low-scoring game,” Louisiana coach Gerry Glasco said. “We thought it would be a 1-0, 2-1, 3-2 game. Obviously we wanted to win. The game played out exactly like I thought it would, but we just didn’t get a hit. When you have a runner and third with nobody out, you’ve gotta put the ball in play. We didn’t get the job done.”

Heebner (26-9) held the 21st-ranked Cajuns to just two hits and three walks in her seven innings in the circle and struck out two of the 25 batters she faced.

“I knew my team was going to be behind my back, and my defense was definitely there tonight,” the junior said. “And the offense came through. We had a lot of hits, and Arielle really started us off really well with the home run and just got the rest of the team involved and excited. They just played their hearts out tonight.”

Even when UL-Lafayette had opportunities with runners in scoring position in the second and sixth innings, Heebner and company came out unscathed.

A double and error to lead off the second put two Cajuns in scoring position with nobody out.

But a strikeout and two groundballs quickly ended the threat.

“You’ve got a bunch of young players that haven’t played a lot,” Glasco said. “You’ve got a big part of your lineup that’s never played before. And the pressure. You’ve got Mr. Octobers, and you’ve got Mr. Mays. You’ve got kids that have got to learn to adjust and get it done under pressure.”

A walk and sacrifice bunt put a potential tying run at second with one out in the bottom of the sixth.

Leadoff batter Kelli Martinez advanced to third on a popup to foul territory to the left side.

But another strikeout extinguished that opportunity.

“We were extremely well prepared,” Glasco said. “We watched film and film and film, and we knew exactly what pitches she was going to throw. We were prepared for it. We only had two strikeouts all night, and those two strikeouts were with runners at third base. That’s not an accident. There’s a reason for that. And we’ve got to bow our necks and become a mentally tougher team.”

For her part, Cajuns sophomore Summer Ellyson said she felt unfazed by the big stage and the unusual schedule.

The Cajuns’ pitcher allowed just five hits and two walks and struck out nine of the 29 batters she faced in her own complete-game effort.

“My heart goes out to her to pitch a game like that and we don’t get her two runs to win the game,” Glasco said. “It’s just really unacceptable on our part. But I’m really proud of Summer for how she’s pitched all year. And tonight was no exception.”

Houston advances to face the host LSU, a 9-0 winner over Fordham in a game that finished late because of the weather delay.

That matchup will begin Saturday’s action at noon.

“Now that we’re here, our objective is to stay in the winners’ bracket,” Houston coach Kristin Vesely said. “We’re going to stay to watch this game and make sure that both opponents look like they look on film. We’ll keep notes and have a game plan for tomorrow.”

Louisiana-Lafayette will attempt to bounce back from itsfirst loss in a regional opener since 2011 in a 2:30 p.m. elimination game.