Australian heavyweight Tai Tuivasa has sunk to his fifth straight defeat after losing to Jairzinho Rozenstruik by split decision at UFC 305 in Perth.

Tuivasa got pummelled in the second round of Sunday's battle at a sold-out Perth Arena, but surprisingly one of the judges scored the three-round bout 30-27 to the Australian.

The other two judges scored the bout 30-27 and 29-28 to Rozenstruik, meaning Tuivasa hasn't tasted victory in the octagon since February 2022.

In a bid to end the rot, Tuivasa had flown to Dubai to train for his latest fight, hoping the change in scenery would help him escape distractions such as his friends and the pub.

The opening round was a subdued affair, with neither fighter able to land any rattling blows.

The second round exploded to life with two minutes remaining when Rozenstruik pounced after Tuivasa hurt his leg while kicking.

Rozenstruik landed a series of heavy blows to leave Tuivasa bloodied and fighting for survival, but the Australian managed to swing back a few times to ensure he made it to the bell.

Tuivasa copped some more lusty blows in the third round, and his late flurry of punches in an attempt to score a knockout fell well short.

Brazilian welterweight Carlos Prates scored a second-round knockout victory over China's Li Jingliang to kick off the main card.

During the preliminary bouts, Australian Jack Jenkins defeated Herbert Burns by technical knockout in the third round of their featherweight bout.

But there was controversy in the heavyweight battle between Russian Valter Walker and Junior Tafa.

Walker won by a technical submission ankle lock in the dying seconds of the opening round after the referee apparently heard a verbal tap-out, but Australian Tafa was adamant he didn't tap out.

Tafa confronted Walker and slapped him after the bout, before the pair were separated.

Ricardo Ramos defeated Australian Josh Culibao by split decision in their featherweight bout.

In the women's flyweight battle, Casey O'Neill won by unanimous decision against Luana Santos.

Du Plessis chokes Adesanya into submission

Meanwhile, Dricus du Plessis defended his middleweight crown after choking arch rival Israel Adesanya into submission during the headline fight at UFC 305 in Perth.

In a bout in which both fighters went all out, du Plessis landed some huge blows late in the fourth round to turn the contest in his favour.

A left hook stunned Adesanya, before three rights helped bring him to ground.

Du Plessis then rolled Adesanya over and put on a rear naked choke, with the New Zealander tapping out seconds later.

"This man is the king of getting back up," du Plessis said of Adesanya, who was bidding to become a middleweight champion for the third time.

"I'm still alive, that's a bonus.

"I came here to die for this belt and to take a life. I'm still champion, baby."

Adesanya said he was disappointed to lose.

"I knew it was going to be tough. I was cracking him," Adesanya said.

"I was quite strong in there. I felt able to resist his takedowns.

"I just make a stupid, dumb mistake on the ground."

And as for the future?

"This is the best I've ever felt. I'm 35, I'm doing the right things. I'm not … leaving," Adesanya said.

AAP