Unfinished business took just a tad longer to settle for Oahu Interscholastic Association Red East baseball rivals Kailua and Moanalua.

The second-ranked Surfriders outlasted the third-ranked Na Menehune 6-5 in eight innings in a typically tight battle, dealing Moanalua (8-1-1) its first loss in OIA play.

Host Kailua (9-0-1) assumed sole possession of first place in the division and claimed the seeding tiebreaker against Moanalua for the OIA tournament with two games to play in the regular season.

The teams tied 6-6 in an extra-innings game called due to darkness on Wednesday, and for a while it seemed this one was headed to a similar conclusion.

But Surfriders senior right-hander Ryan McMonigle had other ideas.

He won the game at the mound and at the plate with an effective relief appearance in the top of the eighth, coupled with the deciding RBI infield single to short in the bottom of the frame.

“Moanalua’s a tough team. It’s always a fun game to play against them,” Kailua coach Corey Ishigo said. “The games are always close; it always comes down to the end. But our players and coaching staff gets along well with them and it’s a friendly rivalry.

“It’s not anything that we hate each other. It’s good fun baseball for us. We should play each other every day.”

Riejg Alo-Chang led off the final inning with a single for Kailua. Catcher Kea Vierra struck out looking, but Kory Sasaoka followed by reaching first on a bunt and subsequent Na Menehune throwing error, advancing Alo-Chang to second.

Another mistake cost Na Menehune dearly.

Moanalua reliever Jordan DePonte was called for a balk while wheeling toward first for a pickoff, moving the runners to second and third.

McMonigle, who went 3-for-4, was down 0-2 in the count at that point but knew what to look for.

“I had a feeling a slider was coming. Sor I just tried to get a good swing on it, put it in play. They were playing up, so it would have been hard for them to make a play,” said McMonigle, who retired the side on a groundout and two strikeouts in the top of the extra inning.

“Just put a good swing, catch the ball good and good things will happen.”

Moanalua shortstop Timothy Arakawa had to hustle to collect the grounder, and his throw home was wide right of the plate as a hard-charging Alo-Chang slid in for the game-winning run.

The Surfriders mobbed each other in front of their dugout.

“That’s the way the ball bounces, I guess. It was a tough play in the hole, so it’s a hard play to make,” Moanalua coach Scott Yamada said. “Kailua’s a great team. No lead is safe.”

Moanalua led 3-0 early, but Kailua responded with three runs in the bottom of the third and chased Na Menehune starter Todd Tanabuki, who lost his command in issuing four straight walks. McMonigle knocked an RBI single through the infield in the fourth and the Surfriders tacked on another score in the fifth off an error.

Kailua senior Alika Ramseyer-Ho struck out seven in seven innings, but couldn’t protect a 5-3 lead going into the sixth.

Moanalua’s Bronson Shim scored Arakawa with a double off the left-center-field fence and James Higa tied it up at 5 with a sacrifice fly.

Arakawa went 4-for-4 at the plate for Moanalua.