Alexander Volkanovski vowed to keep “proving all them doubters wrong” after he retained his featherweight title at <a href="https://www.thenationalnews.com/tags/ufc/" target="_blank">UFC 266</a> following a stunning five-round clash with Brian Ortega on Sunday morning. The Australian, making his first appearance since his successful first title defence in Abu Dhabi last summer, recorded his 20th consecutive professional victory in mixed martial arts via unanimous decision in Las Vegas. Volkanovski had began well, impressing in the opening two rounds, but in the next was forced to somehow escape two choke attempts from Ortega – much to the amazement of the capacity crowd at T-Mobile Arena. The champion, 32, still finished the round raining down heavy blows on his seemingly exhausted opponent. Ortega, beaten only once previously in 16 pro MMA outings, was then inspected thoroughly by the doctor between rounds and subsequently deemed OK to continue. In the end, and after surviving another choke attempt in the fourth, Volkanovski emerged the clear victor, with scores of 49-46, 50-45, 50-44. "I'm a normal human being,” he told Daniel Cormier in the octagon afterwards. “I've said it time and time again. Just hard work got me to where I am. All them doubters, I'm going to keep proving you wrong time and time again. “I don't care. I'll be an underdog until the day I die. Bring it." Defending the belt for the second time – he defeated former champion Max Holloway on Fight Island in July last year – Volkanovski’s past 10 victories have come in the UFC. The bout against Ortega received a bonus from the promotion for fight of the night. In the night’s co-main event, flyweight champion Valentina Shevchenko dominated Lauren Murphy before sealing a fourth-round TKO to equal Ronda Rousey's record for successive UFC title defences by a female fighter (6). The Kyrgyzstan athlete, 33, now has 22 pro wins in mixed martial arts. Elsewhere, Nick Diaz lost on his much-anticipated return to the octagon, going down in his rematch against Robbie Lawler via third-round TKO. The pair first met in 2004, when Diaz won, but the popular American could not replicate the result after six years away from the UFC. "I'm glad I at least put on the show,” Diaz said inside the octagon. "I don't have no excuses. I had a long time off and I knew I had it coming."