Something has to give Friday night when Kaua'i (8-0) plays Waipahu (8-2-2) at Lihu'e's Vidinha Stadium in the First Hawaiian Bank Division II Football Championship semifinals.

Either Waipahu will become the first O'ahu Interscholastic Association team to win a state tournament game on the Garden Island, or Kaua'i will defeat an O'ahu opponent for the first time in the postseason.

For both teams, a spot in the state championship game would be a first.

"We still have a lot to prove," said Kaua'i coach Keli'i Morgado, whose Red Raiders are making their third straight state tournament appearance. "We were pleasantly surprised to get the No. 1 seed, but we've never beaten an O'ahu team (in the postseason), so we've got a chance to do something we've never done before."

This time, Kaua'i has several things working in its favor. Vidinha Stadium has proved to be a dangerous pitfall for visiting teams in past state tournaments, as Kailua (1999 and 2002), Castle (2001) and Pac-Three (2004) all fell victim there.

The Red Raiders also are enjoying the benefits of two straight bye weeks, allowing them to heal from injuries and scout upcoming opponents.

"When you get to the playoffs, you're going up against the best teams in the state, and it leaves you battered and bruised," Morgado said. "After we played Campbell (in the 2004 DII state semifinals), I don't know if we could have played another game if we had won because we were so banged up. Now we're fresh and rested, and we've had a chance to heal up."

The time off also allowed Morgado and his staff to get an up-close look at Waipahu.

"I got to watch them at Aloha Stadium (against Kaimuki on Nov. 10) and at Kamehameha-Hawai'i (last Friday)," Morgado said. "They're big and athletic, especially on the interior, and I have a lot of concerns about their option offense. They can run the same play many different ways."

The Marauders also showed their defensive strength in Friday's 27-12 first-round victory, holding Kamehameha-Hawai'i to just 120 total yards.

But Waipahu coach Sean Saturnio said Kaua'i presents a different set of challenges.

"They're definitely deserving of the No. 1 seed," Saturnio said. "They have a great offense in that run-and-shoot attack; their receivers have good speed and can turn a 3-yard catch into a 10-yard gain. And their defense is fast and well-coached. They have close to 11 hats closing in on every tackle."

The Red Raiders' most dangerous offensive weapon is 5-foot-6, 140-pound senior slotback Pono Matthews, who had 20 catches for 492 yards and five touchdowns in six league games. In two games against Waimea, Matthews caught a combined 13 passes for 357 yards and three TDs, including catches of 81 and 64 yards. He also returned a kickoff 80 yards for a touchdown against Kapa'a.

"Pono's an exciting playmaker," Morgado said.

Quarterback Andrew Renaud has other playmakers to go to in running backs Brendan Young and Micah Alayvilla, and receiver Jonathan Gebauer, who at 6 feet 1 is a strong blocker.

"Andrew's job is to make the appropriate reads and distribute the ball," Morgado said. "Against Waipahu, he'll have to settle down because they'll blitz him with big bodies."

Saturnio said the Marauders will try to use ball control as a defensive tactic.

"We need to execute and keep their offense off the field," Saturnio said.

That proved difficult this season for Kaua'i Interscholastic Federation opponents. The Red Raiders averaged 36.7 points per game in winning their third straight title; their closest game was a 21-10 victory over Kapa'a.

Morgado said a large part of their success is a dedicated coaching staff featuring former University of Hawai'i players Mike Tresler, Dirk Apao and Brian Derby. Tresler is the defensive coordinator, and Derby is a highly regarded offensive line coach.

"They're all loyal, hard-working and very knowledgeable," said Morgado, who played for Punahou under current UH quarterbacks coach Dan Morrison and also consults his uncles, UH assistants Cal and Ron Lee. "It's a tremendous staff."

Reach Wes Nakama at wnakama@honoluluadvertiser.com.