With its pick of weapons, the University of Hawai'i chose dart-accurate outside shooting en route to an 81-64 basketball victory over Idaho last night.

A Stan Sheriff Center crowd of 4,090 watched the Rainbow Warriors bury five of their first six 3-point attempts, open a 23-point lead in the first half, and then withstand Keoni Watson's frenetic 34-point effort.

In avenging last month's loss to the Vandals, the Rainbows improved to 17-12 overall and 7-8 in the Western Athletic Conference. The Vandals are 3-25 and 1-14.

"They shot the snot out of the ball in the very beginning," Idaho coach George Pfeifer said. "A couple of times they were open and the basket looked pretty big to them in the first 15 minutes."

The thing is, the Rainbows' original blueprint was to go inside to post player Ahmet Gueye. But UH coach Riley Wallace took out the blue pencil when the Vandals switched to a sagging 2-3 zone.

Point guard Matt Gibson swished a 3 from the right corner, giving the Rainbows a 5-2 lead they would not relinquish.

After Matt Lojeski, who finished with a team-high 20 points, made a 3 and Gibson followed with another, it was 13-4, and the Vandals' confidence, like their zone, was collapsing.

"They switched to that zone and — boom, boom, boom — we popped that zone pretty quick," Wallace said. "They all feed off of each other a little bit."

The Rainbows built leads of 16-7, 34-13 and, with 5:34 left in the first half, 39-16.

"The first 15 minutes, they were a buzzsaw," Pfeifer said. "It was a pretty big and hard buzzsaw."

Wingman Bobby Nash, who hit three of the Rainbows' eight shots from behind the 3-point stripe, credited the comfort of the home arena.

"We had a good week of practice," Nash said. "We were shooting the ball well in practice. We've got those friendly rims. Shooters gotta shoot. They did. ... It's a good thing when you get your shooters hot at the beginning of the game."

Watson, too, was in the groove, amassing a career high for points. His 34 points were the eighth-most in the arena's 13-year history.

The Rainbows packed their man-to-man defense in an attempt to deny Watson's drives to the lanes. Instead, Watson took detours, abbreviating his drives and launching float shots over post defenders.

"He's got a great middle game when he goes in with that floater," Wallace said. "You back off anywhere on the floor, he can shoot the 3s."

In one second-half sequence, Watson sneaked outside of the Rainbows' defensive reach, then buried a shot from 24 feet.

Later, he speed-dribbled into the lane, pirouetted and scored with an off-balance scoop shot.

"I thought I was going to get a foul," said Watson, who admits to being 5 feet 8 1/2. "He had my left arm. I had to cup it and scoop it. I thought I was going to get a foul call, so I went with it."

By then, Watson, who was born in Hawai'i and received his first name from his godparents, heard "oohs" every time he prepared to shoot.

The rim "must have looked good to him," Nash said, noting Watson took 27 of the Vandals' 62 field-goal attempts.

Lojeski, who is 6 feet 6, often played chasemaster with Watson, who would weave through a series of screens.

"Keoni kept running around," Lojeski said. "He's good at getting open. He uses his quickness well. He knows how to use his screens. He's developed his game a lot. He knows how to use the floater. We send him to our big men, and he's shooting over them. You sag off, he's going to shoot it on you."

Wallace said breakdowns occurred when post players did not rotate when Watson broke free off cuts.

But Wallace was willing to accept the tradeoff. No other Vandal starter had more than five points. Darin Nagle, an accurate perimeter shooter, missed his only 3-point attempt.

And the Rainbows were able to prevail despite Gibson missing most of the second half. He departed — for good — after being assessed his fourth foul with 15:42 to play.

"I was able to rest Gibson," Wallace said. "He kept looking at me. Finally, with about a minute to go, I yelled, 'Gibson.' He looks and I said, 'Just checking how you're doing.' He was staring at me the whole time."

Reach Stephen Tsai at stsai@honoluluadvertiser.com.