The Class B South semifinal was up for grabs, and the Spruce Mountain girls’ basketball team needed someone to step up.

Olivia Mastine was ready to oblige.

Mastine took over the game and led the Phoenix to new heights. She scored 13 points, including seven in the fourth quarter, to help No. 2 Spruce Mountain to its first regional final with a 38-24 victory over No. 3 Wells on Tuesday at the Portland Expo.

The Phoenix improved to 19-1 and will play No. 1 Oceanside. Cali Leighton had 10 points and 10 rebounds for the Warriors, who end the season, 17-3.

Mastine began her run after Wells went ahead 23-22 on a Leighton basket with 2:30 to go in the third. Mastine made a basket on the next possession, then hit a step back jumper to put the Phoenix ahead 26-23 at the end of the quarter. She then started the fourth quarter with a pair of free throws, and followed an Aubrey Kachnovich (eight points) basket by cutting through the Wells defense for a pair of layups to make it 34-23 with under five minutes to play.

“I definitely needed to step up and play my game,” Mastine said. “We just had to work harder at that point and give it our all.”

In addition to scoring 11 of Spruce Mountain’s 13 points after it trailed for the last time, Mastine was also the team’s defensive leader with seven rebounds and five steals.

“I’ve come to expect that out of Olivia,” Spruce Mountain Coach Zach Keene said. “She’s unbelievably competitive, she’s cutthroat, she wants that pressure, she wants that moment.”

Spruce Mountain’s defense excelled down the stretch. The Phoenix closed out on shooters and limited Wells’ access to the rim, resulting in the Warriors missing all 15 shots after taking the lead. Wells managed only a free throw in the fourth.

“I think they could feel Wells reeling a little bit, which added to the level they were playing at,” Keene said. “They were just dominant.”

Wells Coach Sandi Purcell said it stung to see her team go cold at the worst time.

“We’d said from the beginning that we were going to focus on our defense, and defense was going to win us that game. Usually our offense translates right from that,” said Purcell, whose team will return nine freshmen and sophomores, including four starters. “It was just a game where we couldn’t see the ball go through the hoop.

“It stinks that it happens in a playoff game, but you have games like that, where the ball just doesn’t fall.”