PORTLAND — Spruce Mountain harassed Oceanside for four physical quarters, but the Mariners’ poise and patience with the ball allowed them to thrive in Tuesday’s Class B South semifinal girls basketball game at the Portland Expo.

Second-ranked Oceanside (18-0) went on to dismiss third-seeded Spruce Mountain (14-6) with 56-34 victory — and left one of the Mariners’ key players, freshman Bailey Breen, in awe.

“I never expected anything like this my freshman year, so it’s really special — especially with this group of girls,” the 6-footer, who scored scored 18 points and pulled down 12 rebounds, said. “I wouldn’t want to do this with anyone else.”

Oceanside goes on to square off against fifth-seeded York (12-5) in the Class B South final at the Cross Insurance Arena in Portland on Friday at 2 p.m.

The Mariners’ defense also held the Phoenix to single-digit scoring in three quarters, but Spruce did have its chances on offense.

“It is a make-or-miss game,” Spruce Mountain coach Zach Keene said. “When you play against a team like that, you have to take advantage of those (looks). Unfortunately, we didn’t, but …

“We don’t back down. We competed the entire time. It is probably the best team (the Phoenix) will play in a long time. (We) came here expecting to win a basketball game, and you can’t question their heart, their toughness and competitive spirit. As I told (my team), I am proud to be their coach. There is no other group I rather walk out of the locker room with than them, regardless of what happened today.”

The Phoenix’s brightest moments came in the third quarter, during which they scored 15 points and Olivia Mastine knocked down three of her six 3-pointers in a row and eventually became the game’s leading scorer with 20 points.

Despite the Phoenix’s third-quarter heroics triggered by Mastine’s long-range strikes, Oceanside continued to build its lead well into the fourth quarter.

“It was definitely physical, but we played back so it was good,” Breen said. “I thought (Spruce) was a good team. They definitely put their heart on that floor and they gave it their all — and that’s all you can ask from a team.”

Guard Audrey Mackie paced the Mariners’ versatile offense with 19 points.

“I think we really played together as a team,” Breen said. “We got the ball one place and we moved it where it needed to go and we didn’t care who scored because (we play) unselfish basketball.”

Oceanside coach Matt Breen was prepped and ready for the Phoenix.

“I watched a ton of film on (Spruce),” he said. “They are physical. They are not going to give you anything. You’ve got to earn everything against them. That’s why we came in expecting (what we had) to do, and that was the mindset we took coming into the game.

“I thought we had good balance. … I figured they would concentrate on the post and then we were able to expose them in other positions by moving the ball around so I was happy with that.”

Statistically speaking, Oceanside outrebounded Spruce Mountain 28-15. The Phoenix made eight 3-poiners to the Mariners’ six.

“We can go through all the what-ifs all we want to, but at the end of the day, basketball wise, we didn’t get it done,” Keene said. “It wasn’t for a lack of heart and toughness.”