Alexander Volkanovski is set to get his rematch against UFC featherweight champion Ilia Topuria, but questions loom over the future of fellow former champion and compatriot Robert Whittaker after a devastating loss.

Whittaker was submitted in the first round of the UFC 308 co-main event in Abu Dhabi by unbeaten Khamzat Chimaev on Sunday morning (AEDT), with UFC CEO Dana White saying the Sydneysider's "jaw popped" and Chimaev saying he heard "a click."

Volknaovski was on hand to watch Topuria, the man who took his title in stunning fashion last February,make his first defence against another former featherweight champion, Max Holloway, in the main event.

Georgia's Topuria scored a third-round stoppage, flooring three-time Volkanovski victim Holloway with a brutal left hook to advance his record to 16-0.

Volkanovski and Topuria shook hands and embraced in the octagon after the fight.

Topuria and White said Volkanovski loomed as the next challenger but the champion added a caveat which might potentially delay a rematch or even prevent it from happening.

"At this point there's no one that deserves the shot more than Volk," said 27-year-old Topuria.

"He's been a great champion, he's a legend in the featherweight division so he deserves a shot without any doubt.

"But at the same time I'm going to take a small break so we'll see how things go in the featherweight division.

"Maybe he has a tough fight with some new contender and it doesn't play out like he's planning and I'm going to have to fight someone else."

White made it clear Volkanovski should get the next crack at Topuria given his loyalty to the UFC and his outstanding record.

"We're not going to say no to Volkanovski, he's been that guy for us any time we needed him," White said.

"When things don't go our way and you've got to call a guy, Volkanovski has always been that guy."

There has been talk of Topuria defending the title against Volkanovksi on the UFC 312 card in Sydney in February.

White said the UFC really needed to get to Spain - where Topuria is based - even if it meant using a large football stadium like the ones Barcelona and Real Madrid play in.

Whittaker was ranked third, 10 places above Chimaev, but the UAE-based Russian fighter started their fight as the favourite and quickly showed why.

The 33-year-old Australian landed a couple of leg kicks but didn't have the chance to throw a punch, as he was taken down after just 15 seconds.

He scrambled hard along the cage in an.attempt to escape Chimaev's clutches but couldn't get fully back to his feet before the submission.

"I felt something was wrong with his chin when I pushed it, I felt some clicks," Chimaev said.

It was only the second time Whittaker had been submitted and the first time in 13 years, but it was a third loss in his last six fights.