YARMOUTH — Junior pitcher Mari Cooper watched her Yarmouth High softball teammates go scoreless for the first three innings Thursday afternoon but wasn’t concerned.

“I knew that we were on it through the first few innings,” said Cooper. “Everyone was making contact. And I just knew that this was our speed, this was what we like to hit. So I had no doubt that we were going to get our bats going by the third or fourth inning.”

That’s exactly what happened. The fourth-seeded Clippers scored all their runs in the fourth, fifth and sixth innings to defeat fifth-seeded Leavitt 6-0 in a Western Class B softball quarterfinal.

Cooper allowed just three hits and struck out nine to shut down the Hornets.

Yarmouth (14-3) will face top-seeded Greely at 4 p.m. Saturday in Cumberland in a regional semifinal. Greely beat the Clippers 12-2 on May 6.

Neither team could mount much offense in the early going. And when they did, the defense usually rose up. Leavitt shortstop Angela Daigle ended the third inning with a diving, backhanded catch of a line drive by Kallie Hutchinson, saving a run.

But the Hornets never got their hitting untracked against Cooper, who didn’t allow a hit until Morgan Knowlton singled with two outs in the fifth.

“That’s been a problem all year,” said Leavitt Coach Kevin Leonard. “Usually (the hits) come in a flurry or they don’t come. Unfortunately, today was a day they didn’t come at all.”

And Yarmouth finally strung some hits together. With one out in the fourth, Cat Thompson tripled to right field, just beating the throw. Then Eleanor O’Gorman singled up the middle off Daigle’s glove to make it 1-0. O’Gorman was sacrificed to second and came all the way around on Cate Ralph’s slow roller to second. Ralph beat the throw to first for a single and O’Gorman never hesitated, sliding in to make it 2-0.

“She made that call on her own,” said Yarmouth Coach Amy Ashley. “I told her to look. We’ve been talking about being as aggressive as we can to manufacture runs. So I was proud of her for making that call.”

O’Gorman said she saw a bobble on the throw to first, then decided to race home. “I knew they weren’t thinking to go home, so I took advantage of it and went home,” she said.

An RBI single by Cooper made it 3-0 in the fifth. Then the Clippers added three runs in the bottom of the sixth, with Leavitt committing two of its five errors. Andrea St. Pierre had an RBI double and Sophie McGrath knocked in another run.

“We’ve had girls step up in every single position and (every) part of our lineup,” said Ashley. “It hasn’t been one girl that has been carrying us the whole time, and I think that makes us a little more dangerous.”