Seeing is believing for the ‘Iolani Raiders.

They got to see the real deal, R.J. Barrett, the nation’s top college prospect. It was a mixture of pain and awe for the Raiders, who saw the 6-foot-7 senior score 33 points, mostly in sensational fashion, to lead No. 2 nationally ranked Montverde (Fla.) to an 89-43 win in Monday’s quarterfinals of the ‘Iolani Prep Classic.

Barrett, who will play at Duke next season, scored 40 in an opening-round win over Lahainaluna on Saturday.

Again, the Eagles were crisp with the ball and Barrett set the tone with no wasted moves, no wasted energy. He shot 15-for-17 from the field, throwing down eight slam dunks in roughly 20 minutes of action.

“We try to be efficient, to do the things you do at the highest levels when there’s help defense. Quick hitters,” Montverde coach Kevin Boyle said.

Most of Barrett’s electric plays were alley-oop lobs from guards Michael Devoe and Andrew Nembhard, but the left-hander’s windmill slam brought some in the packed gym to their feet.

Devoe finished with 15 points, three rebounds, four assists and three steals. Nembhard amassed nine assists in three quarters. Center Filip Petrusev added 12 points, five boards and four assists.

Cole Ale Kadoguchi and Frank Felix each splashed three treys to lead ‘Iolani with nine points. Vance Hamada chipped in five points, as did freshman Andrew Dawson, a 6-3 post who hit a 2 and a 3 in the final quarter as the Raiders’ home crowd celebrated each bucket with a frenzy.

“All my friends were getting autographs from him on Saturday,” Dawson said of Barrett. “But I said no way. We still had to play him on Monday.”

Dawson and senior guard Kawika Lee agreed that seeing Barrett play on YouTube videos or even in person didn’t compare to actually trying to play against him.

“He’s really faster than he looks on videos. I’m never going to forget that,” Dawson said.

Lee had three points and three assists.

“They’re the top guys in the nation. We had lots of adrenaline. It was good to get out there and see where we stand,” he said. “R.J. is basically unstoppable.”

The Raiders kept it competitive for about 3 minutes. Cole Hogland hit a layup on a pass from Lee, and after Felix sank his first 3, ‘Iolani trailed 7-5. Then the visitors from Florida locked down defensively and went on a 17-2 run.

Barrett didn’t score his first points until there were 4-plus minutes left in the first quarter, but that layup was followed by three slam dunks in a row. After Barrett swished a wing 3, the Eagles led 24-7 late in the first quarter.