CORVALLIS — KJ Harrison hit his second three-run homer in two games and Oregon State advanced to the College World Series with a 9-2 super regional victory over Vanderbilt on Saturday night.

The Beavers won the opener of the best-of-three series 8-4 on Friday, a day after reports surfaced that the Beavers' top pitcher pleaded guilty to a molestation charge as a teenager.

The Oregonian/OregonLive detailed the molestation case against left-hander Luke Heimlich when he was 15. Shortly before Friday's game, Heimlich's attorney said the junior had asked to be excused from playing.

Bryce Fehmel (5-2) started Saturday's game for the Beavers (54-4), who won back-to-back World Series titles in 2006 and 2007.

Vanderbilt (36-24-1) started 6-foot-4 right-hander Kyle Wright (5-6), who could be the first-overall pick in the Major League Baseball draft on Monday.

Wright bounced back from a slow start this season. His ERA was as high as 5.59 on April 1. But he yielded one earned run or fewer in six of his last eight starts, improving his ERA to 2.98 going into the start against the Beavers.

He is expected to become the 10th Vanderbilt pitcher selected in the first round over the last 11 drafts.

The Beavers went up 4-0 in the third on Steven Kwan's RBI single and Harrison's 3-run home run. Harrison also hit a three-run shot in the series opener.

Vandy closed the gap to 4-2 in the sixth on Jeren Kendall's run-scoring single and an RBI groundout from Julian Infante.

Wright loaded the bases with two outs in the seventh inning then walked Harrison to make it 5-2 for Oregon State. His replacement, Zach King, gave up a single to Trevor Larnach and two more runs scored.

Cadyn Grenier added a two-run triple for the Beavers in the eighth.

Wright retired after 6 2/3 innings, with seven runs and eight hits with eight strikeouts. Fehmel pitched a complete game, allowing five hits and two runs. He struck out 10.

Fans chanted "Oh-Ma-Ha" for the final out.

Heimlich, 21, pleaded guilty in 2012 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.

On Friday, he released a statement through his attorney.

"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," the left-hander said in the statement.

It was unclear when, or if, Heimlich would return.

"He's a team guy and in his statement he said that he didn't want to be a distraction," Oregon State coach Pat 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."

The Beavers have advanced to the postseason 17 times. After they were snubbed for an invitation last year, the team responded with a dominant season.

Oregon State went 27-3 in Pac-12 play for the league title, surpassing Arizona State's record of 26 league wins set in 1981. The team's four losses in the regular season were the fewest since Texas was 53-4 going into the tournament in 1982.

Ranked No. 1 at the end of the regular season, the Beavers were the No. 1 national seed in the postseason.