In a second half that was wholly destructive, UC Santa Barbara overpowered Hawaii for a 75-54 basketball rout before 4,653 in the Stan Sheriff Center on Saturday night.

The Rainbow Warriors’ worst loss of the season dropped them to 13-8 overall and 4-3 in the Big West. The Gauchos improved to 16-5 and 5-2, ascending into a second-place tie with Cal State Fullerton.

“Tough game,” UH coach Eran Ganot said. “We didn’t play well. It was our worst game of the year. We didn’t play well on either end early. First half, we defended well. We didn’t do anything well in the second half.”

After the intermission, the Gauchos seized the second act. The Gauchos scored 45 second-half points on 65.4 percent shooting.

They found inside-outside production from Amadou Sow, a 6-foot-9 freshman from Mali, and 6-3 guard Max Heidegger. Both finished with 20 points, amassed in different ways. Sow found the basket on baby hooks and layups off twisting moves. Sow also suctioned 11 rebounds, including four off the offensive glass.

Heidegger connected on three 3s and made all seven of his free throws.

“We couldn’t guard them,” Ganot said.

The Gauchos, who led 30-26 at the end of the first half, dominated after that. Eddie Stansberry’s 3 cut the UH deficit to 38-33 with 13:52 to play, but the ’Bows would not score for another five minutes. UCSB scored 16 unanswered points and never looked back.

The Gauchos relied on a spread-and-shred tactic in which the guards stormed the lane for layups or tosses to the post players. They also were able to create isolation plays in the low post. When the ’Bows collapsed their man-to-man defense, the Gauchos unwrapped their deep-shooting attack. After hitting one 3 in the first half, they drained four treys in the second.

“You know, I think we just defended and rebounded,” UCSB coach Joe Pasternack said of the second-half surge. “It was one of those nights. Hawaii wasn’t making shots. I mean, I think they’re one of the top two or three teams in our league. Eran does an amazing job coaching. They’re always tough to prepare for. You know, it’s just one of those nights. We were making shots and they weren’t.”

The Gauchos, who entered with the league’s stingiest defense, held the ’Bows to 37.7 percent shooting, including 2-for-12 from behind the 3-point stripe.

“We hung in there when we were struggling and it eventually opened up for them,” Ganot said. “Give them credit for out-competing us. That was the bottom line. Second-chance points, around the paint, their strong finishes as opposed to our flips. It was disappointing. We own it. I didn’t have our guys ready to go.”

The ’Bows also were hit by early foul trouble. Jack Purchase, one of UH’s top sharpshooters, picked up his second foul with 9:28 left in the first half. He did not take a shot in the first half. His first basket came with 7:28 remaining in the game.

Heidegger, meanwhile, had his best outing of the season. Named to the All-Big West first team after averaging 19.1 points last season, he suffered a concussion during the offseason and missed the Gauchos’ first nine games. Heidegger returned, but his accuracy did not. He averaged 7.3 points on 24.3 percent shooting since his return.

“Max is a great player,” Pasternack said. “I don’t see that he broke out tonight. I see what he does every single day in practice. He’s a great player. He’s an elite shooter. And he defended excellent.”