The Australian southpaw survived some trouble in the seventh round and knocked Mikaelian senseless with a four-punch combination in the ninth to win their cruiserweight title bout by technical knockout at T-Mobile Arena.

Referee Harvey Dock counted a knockdown for Opetaia because the ropes kept Mikaelian from going down and determined Mikaelian shouldn’t continue.

Opetaia became the first opponent to knock out Mikaelian in the co-feature before Ryan Garcia defended his WBC welterweight title against Conor Benn in the main event of this Ring and Zuffa Boxing card.

“He clipped me,” Opetaia told The Ring’s Max Kellerman of the right hand Mikaelian landed in the seventh. “I’m a bit used to getting clipped in a fight … But I’m still here, I’m still undefeated and, like I said, who’s next?”

Opetaia, 31, won the WBC cruiserweight crown from Mikaelian and retained his Ring and Zuffa titles. The IBF stripped Opetaia of its crown two weeks after he beat Brandon Glanton by unanimous decision March 8.

Sydney’s Opetaia (31-0, 24 KOs) went off as a 16-1 favorite over Mikaelian (28-4, 12 KOs), The Ring’s No. 5 contender.

Armenia’s Mikaelian, 35, lost the WBC belt he won back from Badou Jack in his previous bout via unanimous decision in their immediate rematch December 13.

Opetaia hopes his victory sets up a title unification fight with WBA/WBO champ David Benavidez next.

Benavidez (32-0, 26 KOs), who is The Ring’s No. 1 contender, watched from ringside and drew a loud reaction from the crowd when he was shown on the big screen after the first round.

Benavidez and Opetaia respectfully came face to face after the fight, shook hands and agreed to square off next.

“That’s why I respect this man so much,” Benavidez said of Opetaia’s willingness to fight him. “He’s the boogeyman of the division, but I’m the person they call when it’s time to kill the boogeyman.”

Opetaia gave Benavidez a glimpse of what he could encounter if they fight in the ninth round. His right-left-left-right combination disoriented Mikaelian and made him stumble back into the ropes, which led to the stoppage.

Dock gave Mikaelian time to recover from a low blow with 1:23 to go in the eighth round.

Opetaia’s outboxed Mikaelian for three straight rounds before getting nailed with a right that seemed to buzz the heavily favorite 55 seconds into the seventh. Opetaia took an awkward step after absorbing that punch, held tightly and eventually wrestled Mikaelian to the canvas.

Opetaia clinched some more once the action resumed and was the aggressor again later in the seventh.

A left uppercut by Opetaia, followed by a right to the body, made Mikaelian move away from him for the first time in their bout just before the midway mark of the fourth round. That was the first sign Opetaia could hurt his opponent, who was in control and boxed effectively to that point.

After two nondescript rounds, Mikaelian landed numerous right hands during the third and defended himself well when Opetaia attempted to counter. Mikaelian was warned, however, for hitting Opetaia with a right after the bell sounded to end the third.

Da’Mazion Vanhouter, pushed by Zuffa Boxing as America’s next heavyweight worth watching, knocked out Raphael Akpejiori in the first round of a scheduled 10-rounder before Opetaia defeated Mikaelian.

Vanhouter (13-0, 10 KOs), of St. Petersburg, Florida, dropped Akpejiori with a right-left combination a little less than a minute. He answered referee Robert Hoyle’s count at nine, but he didn’t last much longer.

Vanhouter suffered a minor shoulder injury as Akpejiori tried to tie him up, but he broke free, landed two more right hands and knocked him flat on his back. Hoyle immediately waved an end to their bout at 1:58.

Miami’s Akpejiori (19-4, 18 KOs) lost by knockout for the third time. The 6-foot-8 Nigerian was previously stopped by American Stephan Shaw (21-2, 16 KOs) in the first round 17 months ago and Russian Arslanbek Makhmudov (21-3, 19 KOs) in the second round in July 2023.

Vanhouter, 21, made his pro debut as a junior middleweight in April 2022. He recorded his seventh straight knockout against Akpejiori, all since he moved up from cruiserweight to heavyweight following a six-round, split-decision win against Cristian Davalos Rodriguez in April 2024.