Alex Volkanovski defended his featherweight belt after overcoming Brian Ortega in one of the most dramatic fights of the year at UFC 266.

Volkanovski withstood two submissions in a brutal showdown with Ortega in Las Vegas, where the Australian champion prevailed by unanimous decision (49-46, 50-45, 50-44) on Saturday.

Ortega (15-2) – largely outclassed – looked to be on the brink of victory after a mounted guillotine and then a triangle choke in the third round left Volkanovski in trouble at T-Mobile Arena.

But Volkanovski (23-1) silenced his critics, emerging from the jaws of defeat to celebrate his 10th consecutive win in the UFC.

"All you doubters, I'm going to prove you wrong time and time again," Volkanovski said in his post-fight interview.

"Bring it. About f****** time [you put respect on my name].

"Keep doubting me. I love it. I'll be underdog to the day I die."

Of the submission attempts, Volkanovski – who has not lost since May 2013 – said: "Some of them were pretty tight.

"For some reason I went to the ground with him. Obviously, he's good. ... I thought I was in his head and he came back even stronger."

Ortega added: "I thought it was done. That's what we trained for my entire camp. ... That little bastard is f****** tough as hell."

In the co-main event, Valentina Shevchenko completed her sixth straight title defence at the expense of Lauren Murphy.

Shevchenko (21-4) scored a devastating fourth-round TKO against Murphy in the flyweight title showdown.