APTOS >> Star senior forward Isaiah Ackerman and the No. 1 seed Aptos High’s boys basketball team didn’t look past Sacred Heart Cathedral in the Central Coast Section Division III semifinals on Thursday night.

How could they? The Fightin’ Irish compete in the powerful West Catholic Athletic League and beat Santa Cruz County foe Santa Cruz for the D-III crown last season.

No, the Fightin’ Irish — a 13-time section champion, two years removed from winning the prestigious Open Division title — had the Mariners’ full attention and utmost respect. So Aptos gave them its ‘A’ game — which included its trademark fierce defense, mixed in with a consistent offensive attack, both in its half-court set and transition.

Ackerman filled out the box score with 29 points, nine rebounds, five blocks, four assists, and three steals, and the Mariners trailed just once in their 65-43 win over No. 4 Fightin’ Irish.“It means a lot,” Ackerman said. “They’re WCAL, great league, great coach. It’s huge, especially winning at home in front of our home crowd, and having a chance to play for a title.”

With their win, the Mariners advance to a section final for the seventh time in school history. They’re seeking the program’s first title since 1986. To accomplish that, they’ll need to get past a familiar foe, league rival Santa Cruz, a two-time champion and 13-time finalist.

The Mariners (24-4 overall), the Santa Cruz Coast Athletic League champion, and runner-up Cardinals (17-11) square off in the section final at Mission College in Santa Clara on Saturday at 1 p.m.

Aptos has beaten Santa Cruz three times this season, but all three contests were decided by four points or less.

“It’s gonna be fun,” Mariners coach Brian Bowyer said. “I’m glad Santa Cruz is there; I’m glad they made it. I’m happy for them, but playing a team four times is not fun. Every game we play against them seems like it gets a little uglier and ugller, just because we know each other so well. And this game we know each other better than last game. So I’m expecting a really tight game, something that comes down to the wire.”

The Mariners wisely stayed focused on SHC rather than looking ahead to a possible fourth matchup against the Cardinals.

Ackerman scored 19 of his points in the first half, and he handed the baton to Nick Tovani in the second half, when the senior guard produced 14 of his 18 points. Senior center Owen Warmerdam chipped in with six points.

“Our game plan was to force him (Ackerman) left, initially,” said Isayah Kennedy, a sophomore guard for SHC, “but there wasn’t much we could do. We played hard; we tried out hardest.”

SHC (10-16) graduated nine seniors from last year’s section championship squad, leaving the team with a senior-less group to uphold the program’s rich tradition for winning it all. The squad went 2-12 in the WCAL this season, but the Mariners respected what they saw from the Fightin’ Irish on film: a high-pressure defense that loves to press and score in transition when its wasn’t knocking down 3s.

“They’re definitely a super pressuring team, and we had to take advantage of that,” Tovani said. “And I think we did. We got a lot of fast-break points and that was big for us.”

Senior guard Ryan Solorio buried a 3-pointer early in the first quarter to spark a 11-0 run and give the Mariners the lead for good.

The Mariners navigated through SHC’s press with relative ease for some big finishes at the rim and jumped out to a 17-7 lead by the end of the first quarter.

SHC sophomore guard Kiran Tate-Day suffered an apparent knee injury in a mosh pit below the Irish’s rim as players battled for a rebound with 6:12 remaining in the second quarter. He was carried off the court in tears and didn’t return.

The Mariners went on another run with Tate-Day sidelined and carried a 30-18 lead into the half.

Aptos dared SHC to penetrate its zone defense with Ackerman and Warmerdam waiting for some big-time swats in the paint. Tovani also got in on the action.

“Owen and Isaiah in the back, they just did such a great job protecting the rim,” Bowyer said. “They weren’t shooting the ball very well and they were having a hard time scoring around the rim with our length. I’m so happy. We made shots; the whole game we made shots — first time in a while. I’m just so proud of how they played. It was a great game for them.”

Tovani made two 3-pointers, including a casual dribble past half court and bomb from NBA range, and the Mariners blew the game open in the third quarter. They entered the fourth with a commanding 50-28 advantage.

“It means everything,” Tovani said. “A lot of these teams from over the hill come in thinking we’re not very good and we got to show ’em tonight by what, 22? So it feels really good.”

SHC didn’t back down. The Fightin’ Irish returned to their press and played rough defense when Aptos drove into the paint. The Mariners made SHC pay when they were fouled, too. Aptos finished 14-of-14 shooting from the free-throw line.

Eventually, Bowyer emptied his bench and the Mariners reveled in victory.

Kennedy led SHC with eight points. Junior guard Cory Wong scored seven points, and junior forward Ilias Medios chipped in with six points.