On Saturday night in Singapore, Prochazka submitted Teixeira at 4:32 of the final round, putting an end to a grueling and thrilling title fight.
The 42-year-old Teixeira, who became a first-time UFC champion at 205 pounds (93kg) late last year, put Prochazka through nearly five rounds of consistent punishment.
After a back-and-forth fight that left both men cut and bleeding, the Czech challenger got into position to execute a choke that ended one of the most compelling title bouts in recent UFC history.
It was Prochazka’s first victory by submission in UFC and his first since 2014. He has won 13 straight bouts. Teixeira won the belt at UFC 267 last October, defeating Jan Blachowicz.
“It was a true war,” Prochazka said. “Glover is a true warrior. And I like that.”
Teixeira (33-8) was up 39-37 on two scorecards heading into the fourth round, which means the Brazilian champion almost certainly would have won a decision if he had avoided a submission in the final minute.
Both fighters landed big shots from the opening round, and Teixeira appeared to turn the bout in his favour when he hurt Prochazka in the second round, eventually landing an elbow that opened a big cut above Prochazka’s left eye.
Both fighters were bleeding from cuts in the third round, and Prochazka also wobbled Teixeira in the middle rounds before his dramatic finish.