YORK — Everything fell into place for the York High School baseball team during last season’s run to the Class B state championship.

It took one tournament game for the Wildcats’ magic to run out this spring.

Dalton Therrien led off the top of the seventh inning with his second home run of the game, propelling fifth-seeded Oak Hill to a 5-4 victory over No. 4 York in Wednesday’s Western Maine Class B quarterfinal.

“Last year we were the team that had balls fall in for hits or got that two-out double,” York coach Chuck Chadbourne said. “Today they had two very important hits, and that was the difference.”

York finished the season at 10-7. Oak Hill (13-4) advanced to Saturday’s regional semifinals to play the winner of today’s game between No. 8 Wells (9-7) and top-seeded Lincoln Academy (12-4).

“They were the defending champion, a good ball team and well-coached; it was a tall order,” Oak Hill coach Matt Bray said. “For our kids to come here against a team that’s really battle tested, this far away from home, I’m really, really impressed. They came out fresh and played great defense. When we play great defense, we win.”

The Raiders took a 4-3 lead in the fifth following a solo homer from Therrien and a two-run shot by Jake Martin off York starting pitcher Dan Bock. Wildcats junior Cole Merritt tied the game at 4-4 with a home run against Oak Hill’s Parker Asselin to lead off the bottom of the sixth.

Therrien, who carried a .491 batting average into the game, greeted freshman reliever Trevor LaBonte by crushing a fastball to left field for a 5-4 Oak Hill lead in the top of the seventh.

“Dalton is a heck of a player,” Bray said. “He hits for power, he can bunt, and he made all the plays in the field today. He deserves a lot of credit.”

Chadbourne said he went to the bullpen because he was concerned that the top of Oak Hill’s lineup had figured out Bock.

“I thought the way (LaBonte) had been throwing, that if he could get his curve over he’d be OK,” Chadbourne said. “He threw fastball down the middle of the plate and (Therrien) turned on one.”

Asselin scattered nine hits in a complete-game effort, retiring the Wildcats in order in the seventh. After York grabbed a 3-0 lead in the third on an RBI double by Chris Nielson (two hits) and a two-run double by Merritt, the right-hander limited York to three hits the rest of the way.

“They had bigger hits than us and I just felt like they played harder,” Merritt said. “It’s baseball; you can’t win them all. It’s a big difference from last year.”

Chadbourne didn’t know what to expect after 10 seniors graduated from last year’s championship team. Adam Legg is the only senior this year, meaning the Wildcats should return plenty of experience next season.

“I couldn’t be any happier with how we played this year,” Chadbourne said. “It’s been a roller-coaster year. They’re upset right now, but I can’t complain about their effort.”