Kaiser High School's baseball team of "overachievers" did it again yesterday, holding off Waiakea, 2-1, in the Wally Yonamine Foundation Baseball State Championship quarterfinals.

Sophomore Zach Wong and senior Toby Inouye combined on a five-hitter and the Cougars scored both runs on a two-out error in the second inning at Les Murakami Stadium.

Kaiser improved to 11-5 in the regular and postseason and will face O'ahu Interscholastic Association champion and No. 2 seed Pearl City (12-3) in today's 5:30 p.m. semifinal.

It is the Cougars' first state semifinal appearance since 1997 and comes one year after they graduated eight starters.

"Who in their right mind thought we would be where we're at now?" Kaiser coach Peter Ho said. "The whole island is probably wondering, 'Why is Kaiser in the state semifinals?' (But) these kids are incredible. They're making me a believer."

Big Island Interscholastic Federation champion and No. 3 seed Waiakea (12-2) took a 1-0 lead in the top of the second inning after Richie Chinen led off with a walk, advanced to second base on Thad Yasuhara's sacrifice bunt and scored on Rory Inouye's single to center field.

Kaiser then put runners on second and third with two outs in the bottom of the inning, and an infield error led to both runs scoring.

The Warriors almost got the same kind of break in the fourth, when the Cougars committed a two-out error with runners on first and second. But Waiakea's lead runners got caught in a rundown and Kaiser got the final out with a tag at third base.

"We made a base-running mistake, but I'm not going to pin this loss on one play," Warriors coach Gordon Mau said. "We had many opportunities, runners in scoring position, but we didn't get the key hit when we needed it."

Wong pitched five innings and Inouye, who threw 93 pitches in Wednesday's seven-inning complete game victory over Kaua'i, pitched the final two to earn the save. Inouye said his right pitching arm "was all tight" when he woke up yesterday, but it loosened up during warm-ups for the 9 a.m. game.

"(Ho) asked me before the game if I could pitch, and I told him I felt good," Inouye said. "I knew it would be OK when the time comes."

Reach Wes Nakama at wnakama@honoluluadvertiser.com.