BATON ROUGE, La. — Even on a day with a heat index of 103 degrees, it snowballed quickly for the 24th-ranked West Virginia baseball team.

The Mountaineers led 1-0 in the fourth inning of Game 1 of the Baton Rouge Super Regional, but seven runs in the span of as many batters turned the series opener into a 16-9 LSU rout.

LSU (47-15) scored three runs in the fourth and seven in the fifth to take a 1-0 lead in the series, forcing WVU (44-15) to win the next two days if it is to reach its first College World Series in program history.

“We played competitive baseball,” WVU head coach Steve Sabins said. “The game slipped away from us out of the bullpen. We asked a lot of guys to compete at a high level, quite a few kids that hadn’t been in a scenario like that before.”

WVU starter Griffin Kirn battled through the first three innings and even had a 1-0 lead thanks to Jace Rinehart’s second inning RBI single, but the warning signs were there. Kirn hit a batter and fell behind 3-0 in another count in the second, walked the lead-off man in the third and hit two of the first three batters in the fourth.

Finally, the bill came due for his command issues.

LSU freshman Derek Curiel served a three-run homer out to left field, igniting the 12,093 strong home crowd and starting West Virginia’s rapid unraveling.

“I didn’t think Kirn was quite as sharp,” Sabins said. “And it probably had something to do with the fact that he threw twice in a week for the first time all season last weekend. He started game one of the regional and closed out the regional, and then obviously the conditions today being so hot, so humid, a little bit shorter rest for him, he wasn’t quite as crisp.”

Kirn made it through the fourth inning without further damage, but allowed a lead-off single in the fifth. The single came around to score, and a combination of three relievers — JJ Glasscock, Cole Fehrman and Tyler Hutson — allowed six more runs in the inning as the Tigers put the game out of reach. Back-to-back walks set the table for shortstop Steven Milam, who shot a grand slam out to right field.

“We have a really good team,” Sabins said. “It takes our depth and it takes everybody if we’re going to win at the highest levels. We didn’t think that he [Kirn] was the best option there.”

Milam’s slam was actually the first of two on the day for the Tigers. One inning later, another procession of walks teed up Josh Pearson for a grand slam of his own with all three runners in front of him reaching on free passes.

West Virginia pitchers issued a season-high tying 13 free bases between eight walks and five hit batters, and LSU scored 10 of them in.

All of it laid waste to the only real positive of the day for the Mountaineers, a strong offensive outing against Kade Anderson. The Mountaineers pounded out seven runs on nine hits against the likely top-10 overall pick in next month’s MLB Draft, Anderson’s career-high allowed in both departments. Skylar King and Chase Swain provided the biggest blows of a four-run sixth inning, and Gavin Kelly hit West Virginia’s first home run of the game, a two-run shot in the seventh. Kyle West added a towering two-run homer of his own off LSU reliever William Schmidt in the ninth, giving the Mountaineers their third consecutive game with at least nine runs.

“Working a pitch count is one thing,” designated hitter Sam White said about the approach against Anderson. “But if he gives you something to hit you’re not trying to foul it off, you’re trying to hit it.”

The score looked a little closer at the end, but the reality of the day was one of the nation’s most talented teams overwhelmed West Virginia. The only positive for the Mountaineers is unlike a regional where a loss in game one requires you to win four straight elimination games to survive, this is a standard three-game series. West Virginia had two series this season, BYU and Texas Tech, where it lost game one and responded to win the next two. This challenge will be much greater, but the mentality is the same.

“They could have beat us 40-0 and tomorrow it’s going to be 0-0 at one pitch,” White said. “There’s nothing to it. It’s a series.”

Game 2 of the series is set for 6 p.m. Sunday. Neither side confirmed a starting pitcher, but it will almost certainly be West Virginia’s Jack Kartsonas to the mound for the against LSU’s Anthony Eyanson.