Portland had only two hits off Falmouth left-hander Reece Armitage through five innings in a scoreless game. The Bulldogs, however, had their ace reliever on the mound and the confidence gained from recent late-inning comebacks.

After rallying in the fifth inning in the regional quarterfinals, Portland broke this one open in the sixth.

No. 7 hitter Jack Nichols drove home two runs with a single to right and Zach Fortin dumped a base hit down the line in left to score another as No. 1 Portland beat No. 4 Falmouth 4-0 in the Western A baseball semifinals Saturday at Hadlock Field.

The Bulldogs (14-4) will play No. 3 South Portland (14-4) for the regional title Wednesday at St. Joseph’s College.

Jake Knop gave Portland a 1-0 lead when he led off the sixth with a single and eventually scored on a fielder’s choice. Then Nichols and Fortin did their damage.

Ryan Ruhlin came on in relief of starter Dan Marzilli with one out in the six and gave up a single, but struck out the next two batters.

Portland turned a double play in the top of the seventh before Colin Coyne doubled to left and Robbie Armitage singled. Ruhlin got the final out on a fly ball to right to earn his seventh win of the season.

“Their pitcher threw great,” said Portland Coach Mike Rutherford. “With Ryan Ruhlin on the mound, the kids feel they just have to get one or two runs to win. He’s not overpowering, but he comes right at hitters. We play solid defense and don’t beat ourselves.”

Falmouth (11-7) outhit the Bulldogs 10-6 but couldn’t string any hits together.

“If you had told me that we would get 10 hits and make no errors, I would have said we’re going to win,” said Falmouth Coach Kevin Winship. “We couldn’t get any momentum. In each of the first three innings, our hit came with two outs. Portland is solid defensively. We started four sophomores and a freshman. I’m really proud of our guys.”

Armitage, one of the sophomores, struck out five of the first batters he faced, and finished with nine strikeouts.

Marzilli also pitched well. He gave up a hit in both the first and the second, then two in the third. He retired the side in order in the fourth, then allowed a one-out single in the sixth to Connor MacDowell and gave way to Ruhlin.

“We have a lot of trust in each other,” said Ruhlin, a senior, explaining his team’s ability to rally. “We have a lot of confidence that we can get it done.”