When Yarmouth’s boys’ basketball team finds itself in trouble, it knows where to turn.

To senior Stevie Walsh, who never lets the Clippers down.

Walsh added another chapter to his postseason legacy by scoring 21 second-half points, helping the defending state champion Clippers hold off Lincoln Academy, 54-50, in a Class B South semifinal Tuesday night at the Portland Expo.

Yarmouth (16-4), the No. 2 seed, won its 12th straight game and advanced to meet No. 1 Oceanside in the regional final at 3:45 p.m. Friday at the Expo.

Walsh, who finished with 23 points, hit three 3-pointers after halftime, then clinched the victory with five free throws in the final 18 seconds.

“I think it’s all the hours I spend in the gym,” said Walsh. “I practice situations where I’m on the line and have to hit free throws to win the game, and I think it correlates to (the game).”

The Clippers went up 16-7 in the first quarter, then made it 18-9 on a breakaway dunk by Evan Hamm early in the second. But the sixth-seeded Eagles (14-6) fought back to trail by only four at halftime, 23-19.

Walsh then came alive, making back-to-back 3s, scoring on a layup after a steal and adding three free throws for an 11-point third quarter, which saw Yarmouth go up by eight before Lincoln rallied within 37-32 heading into the fourth.

Yarmouth led by as much as seven, thanks to seven straight points from Hamm, but the Eagles stayed close before the Walsh iced it at the line.

“In the locker room, we did shout-outs and two people said, if their life was on the line, they’d want Stevie shooting the free throw,” said Hamm.

“Stevie is a great leader,” added Ilunga Mutombo, the Clippers’ first-year coach. “When it comes down to it, he’s the most clutch guy that I’ve ever seen.”

Hamm added 17 points and eight rebounds for Yarmouth, which will make back-to-back regional final appearances for the first time since 2016-17.

“We’ve played a lot of teams this year, and if there’s a team with more resilience than (Lincoln Academy), I don’t know who it is,” Mutombo said. “They kept coming back, coming back, coming back.”

The Eagles got 20 points from Gabe Hagar and 13 from Jacob Masters.

After losing by 40 points to Yarmouth in last year’s preliminary round, Lincoln has closed the gap and will have a strong nucleus returning.

“I’m so proud of my guys,” said Eagles Coach Ryan Ball. “Our kids battled, and that’s what we’re about. We knew if we could keep it close, we hoped we could stun them in the fourth quarter.

“We’re going to get back after it next year. The program’s goal is to get to a regional final. We haven’t done that for a long time.”