Teixeira (33-7) finished the 38-year-old Blachowicz (28-9) by rear naked choke in an impressive upset victory that capped a remarkable late-career surge.

In the co-main event, Petr Yan won an interim bantamweight title with a hard-hitting decision victory over Cory Sandhagen.

Earlier in the night at Abu Dhabi's Etihad Arena, rising stars Islam Makhachev and Khamzat Chimaev returned to the cage with impressive wins.

Champion Blachowicz was a significant favourite in the second-oldest combined title fight in UFC history, but Teixeira earned his sixth consecutive victory in style.

After largely controlling the first round, Teixeira made an exceptional takedown in the second round and worked his way into position to sink the winning choke at the 3:02 minute mark.

Teixeira hadn't fought for a UFC belt since 2014, when his 20-fight winning streak was snapped in a clear decision loss to Jon Jones - who vacated the title as he bids to move up to heavyweight.

He won his sixth straight fight and is second only to five-time champion Randy Couture, who was 43 when he won the heavyweight title in 2007, for oldest fighter to win a UFC belt.

"Twenty years, baby, 20," Teixeira, who made his MMA professional debut in June 2002, said.

"I have no words to describe (this). Never give up on your dreams."

Yan (16-2) reasserted his claim to the bantamweight belt by beating Sandhagen (14-4) in a thrilling match of elite strikers.

Makhachev (21-1) extended his win streak to nine with a first-round submission victory over Alex Volkanovski's City Kickboxing teammate Dan Hooker, ending it with a kimura near the midway point of the first round.

Chimaev (10-0), a popular pick to contend for the welterweight belt in the near future, dominated Li Jingliang in his first fight since early last year due to COVID-19 and other difficulties.

Australian Associated Press