CORVALLIS, Ore. — Oregon State beat Vanderbilt 8-4 in the opening game of their NCAA super regional on Friday night, a day after reports surfaced that the Beavers’ top pitcher pleaded guilty to a molestation charge as a teenager.

On Thursday, The Oregonian/OregonLive (http://bit.ly/2s0uFD8) detailed the molestation case against Oregon State pitcher Luke Heimlich when he was 15. Shortly before Friday’s game, Heimlich’s attorney said the junior had asked to be excused from playing.

Heimlich was in uniform and was cheered by fans when he was introduced along with the rest of Oregon State’s players before the game. Attendance for the game was announced at 3,737, a Goss Stadium single-game record.

KJ Harrison hit a 3-run home run and Nick Madrigal added a two-run double to lead the Beavers. Oregon State, ranked No. 1 in the nation, is the top national seed in the NCAA Tournament. The Beavers have won 20 straight games.

Right-hander Jake Thompson (14-0) started for the Beavers (53-4) in the opening game of the best-of-three series. The winner advances to the College World Series.

“I thought we played with energy,” Oregon State coach Pat Casey said. “I thought we played with the type of togetherness we talk about all the time.”

Harrison’s three-run homer put the Beavers up in the first inning, but Vandy tied it in the second on Jason Delay’s two-run single and Will Toffey’s RBI single to left center.

Madrigal’s double down the left field line scored a pair of runs with two outs in the bottom half.

“They got the big hit twice early and that certainly was kind of a shot to the gut, especially after we came back and scored those three,” Vanderbilt coach Tim Corbin said.

Oregon State added a run on Trevor Larnach’s single to left in the fifth. Toffey hit a solo home run in the seventh to close the gap to 6-4.

With the bases loaded in the eighth, Cadyn Grenier slugged a single and Steven Kwan hit a sacrifice fly to right to pad Oregon State’s lead to 8-4.

Thompson went 7 2/3 innings, allowing four runs and seven hits with seven strikeouts.

Vanderbilt (36-23-1) is vying to reach the College World Series for the third time in four years. The Commodores started right-hander Patrick Raby (10-4), who pitched six innings and gave up six runs and eight hits.

“It’s just one game. It’s history now. They’ll respond tomorrow,” Corbin said about his team.

Heimlich pleaded guilty to a single charge connected to the molestation of a 6-year-old girl in Washington state when he was 15. He completed a diversion program, served two years of probation and attended sex offender treatment for two years. He was also required to register as a sex offender.

“I’m so proud of our team’s accomplishment and don’t want to be a distraction therefore I’ve respectfully requested to be excused from playing at this time,” Heimlich said in the statement released by his attorney.

In his first public remarks about Heimlich, Casey praised his pitcher after the game.

“He’s a team guy and in his statement he said that he didn’t want to be a distraction,” Casey said. “I can just tell you that he is a fine young man and every second that he’s been on this campus, on and off the field, he’s been a first-class individual, one that his family should be proud of, your community should be proud of, our team is proud of. I believe in Luke.”

Casey said he did not know who would start for the Beavers on Saturday. He said it was Heimlich’s decision whether he would make himself available to play.

The Beavers won back-to-back College World Series titles in 2006 and 2007 and have advanced to the postseason 17 times with a 53-33 overall record.

The Beavers went 27-3 in Pac-12 play for the league title, surpassing Arizona State’s record of 26 league wins set in 1981. Along the way, Casey surpassed the 1,000-win milestone.

Oregon State’s four losses in the regular season were the fewest since Texas was 53-4 going into the tournament in 1982.