With front-row players like 6-foot-6 middle blocker Tyler Caswell, 6-4 opposite Cliffton Pires, 6-3 outside hitter/middle blocker Chase Moses and 6-2 outside hitter Timothy Moyer, Kalaheo High School's boys volleyball team has more than enough height to cause big problems for opponents at the net.

But the Mustangs proved last night they can deliver from behind the end lines as well, serving up eight aces in a 25-11, 25-19 sweep of Leilehua in the O'ahu Interscholastic Association semifinals. Kalaheo (13-1) will face OIA Eastern Division rival Roosevelt (13-1) for the championship at 6:30 p.m. Nov. 2 at McKinley's Student Council Gym.

Roosevelt swept host McKinley 25-22, 25-19 in last night's opener of the semifinal doubleheader.

Kalaheo and Roosevelt split their two regular-season matches, with the Mustangs winning the Sept. 5 meeting 20-25, 25-18, 25-21 and the Rough Riders sweeping the Sept. 28 rematch 25-23, 25-21.

Last night, both teams recovered from slow starts and finished strong.

Kalaheo trailed 7-5 before Moyer served the Mustangs to 10 straight points for a 15-7 lead. Pires then served two aces in helping Kalaheo string together an 8-0 run to lead 23-9.

"The main thing we try to do is get the first serve in," said Pires, who finished with five aces. "Then give it all we've got and swing our hardest."

First-year Mustangs coach Gavin Cook said tough serving is a key to his team's success.

"The serve is what starts it for us," Cook said. "We want to serve tough so that we can get the other team to play to our strengths. Our blocking will be better, and if we can get free balls then we'll hit well, too."

Leilehua (11-3) finished in a three-way tie for first place in the OIA West, but entered last night's match short-handed when its starting setter did not suit up for personal reasons.

"We had to make a big mental adjustment," Mules coach Ernest Balignasay said.

Leilehua regrouped in the second game and kept pace until 17-17, but Pires then served seven straight points — including two aces — to help the Mustangs seal the victory.

Caswell finished with six kills and two blocks to lead a balanced Kalaheo effort.

"Their height is a big factor," Balignasay said. "Any team would have to double up on defense against them, because they're always going to come over the top. They're a good team."

Roosevelt, which shared the East title with the Mustangs, pulled away late in both games to sweep East No. 4 seed McKinley (8-7).

The first game was tied 18-18 before the Rough Riders took advantage of two lift violations by the Tigers and Kaina Palama's two kills to pull away.

The second game also was tied at 18-18, but again McKinley made two errors and Kyle Maki's back row spike capped a 5-0 run to make it 23-18.

"Roosevelt is really good at making late runs like they did tonight," Cook said. "(Coach) Kaui (Mendonca) does a great job getting them focused and they don't make mistakes — they let you make the mistakes and decide your fate."

In the OIA Division II semifinals, 'Aiea defeated Kalani, 21-25, 25-19, 25-22, and Wai'anae swept Farrington, 25-17, 25-21. 'Aiea (8-4) will face Wai'anae (12-0) for the championship at 6 p.m. Wednesday at Farrington.

Reach Wes Nakama at wnakama@honoluluadvertiser.com.