BATH  — With an Oak Hill runner at second base in the second inning of a 1-1 Western Class B baseball quarterfinal, Morse pitcher Trent Moore stepped off of the rubber, spun around and whipped the ball into center field.

Or so the Oak Hill runner thought.

Moore still had the ball, but with middle infielders diving and the center fielder charging, his teammates sold the designed play convincingly. The runner broke for third. This time, Moore made the throw — an accurate one — and got a crucial second out in the inning. It was the third of four Oak Hill baserunners erased via pickoff or caught stealing in the first three innings.

Moore went on to scatter nine hits and the third-seeded Shipbuilders, buoyed by their defensive chicanery, proceeded to score four runs in the third inning on their way to a 7-1 win over the No. 13 Oak Hill.

Morse (13-4) will face No. 2 Falmouth in the semifinals. Oak Hill finishes its season 9-9.

“We haven’t used that (play) at all this year,” Moore said. “Our coach just told us about it last practice and we practiced it a few times. It was really important because once you get them off the bases, it’s a lot of weight off my shoulders.”

“It was something we’ve put in within the last week to keep things interesting,” said Morse coach Garrett Olson, who played at Oxford Hills, Franklin Pierce College and in the Minnesota Twins organization. “You know, school’s getting out, kids start to lose interest a little bit. It’s tough to keep motivating and keep them interested and that’s one of the things we put in practice just to have fun and maybe we’ll use it some time. It worked out better than we could have expected.”

Things got off to a promising start for the Raiders in the first when Brady Dion belted a one-out triple and scored on a single by Ryan Riordan, who had three hits. Moore surrendered four hits, two walks and had another Raider reach on an error through the first three frames, but the Raiders only had the one run to show for it because they kept running into outs.

“We had hits. We had baserunners. We didn’t run the bases well,” Oak Hill coach Matt Bray said. “Since I’ve started here, we’ve been working on everything, from hitting to fielding, all of the fundamentals. Baserunning kind of comes last unfortunately. It’s one of those things that kind of comes with time and getting to know the game. It’s something we just don’t do very well, and we were exposed there today.”

Zack Holbrook got the Shipbuilders’ big inning started with a leadoff double. Moore singled to knock him in. Paul Whalen’s RBI single made it 3-1. Ethan Winglass followed with a two-run triple to make it 5-1.

“Hitting is contagious, and they know that,” Olson said. “We’ve got a great lineup. Every guy in it hit over .300 this year and we had three guys that hit over .400, so one through nine, we know we can hit the ball, and it seems like the bottom of the order has been producing for us all year.”

Morse added two more runs in the fourth, and Moore pitched like someone working with a comfortable lead. He stranded two runners in the fourth and gave up a single in each inning thereafter, but the Raiders never got another runner to second base.

“I felt like I was getting stronger,” Moore said. “They were getting hits, but my fielders were backing me up. I wouldn’t have done it without them.”

Oak Hill, which loses five seniors, including three starters, had nine hits, a carryover from its 16-0 upset win over Cape Elizabeth in the preliminaries. Bray expects to be able to build on the playoff experience.

“Overall, I can’t say enough about these kids,” he said. “There’s no way we should have beaten Cape, certainly not 16-0. I’m really, really proud of them. We have a lot of really good juniors, some really good sophomores and some really, really good freshmen, so we’re very excited for next year.”