Antonio Cesar vs Viet Anh Do booked for ONE Fight Night 50 in likely flyweight title eliminator

ONE Championship has matched flyweight finishers Antonio Cesar and Viet Anh Do for ONE Fight Night 50 on Friday, December 18, at Lumpinee Stadium in Bangkok, Thailand. The three-round MMA bout is expected to decide the next challenger for the ONE flyweight title in 2027. ONE confirmed the booking to MMA Fighting, which first reported it on Thursday, November 12.

Cesar vs Do: two in-form finishers

Cesar (15-2), a 22-year-old Brazilian nicknamed "The Flash", goes into the fight on a 10-fight winning streak with four finishes. He is 4-0 in 2026 with three finishes and 2-0 since joining ONE in July. His most recent win was a first-round stoppage of Joshua Perreira in October.

Do (7-0) is a 29-year-old Vietnamese flyweight who began his professional MMA career under the ONE banner in 2019. According to MMA Fighting, he has a 100 percent knockout rate in the promotion, with four of those finishes coming in the opening round. December 18 will be his fourth fight of 2026, and he stopped all three opponents he faced earlier this year.

The matchup puts Cesar's long winning run up against Do's unbeaten record and finishing power. Do has fewer pro fights, but every one of his wins in ONE has come by stoppage.

The champion waiting

The ONE flyweight MMA title belongs to Avazbek Kholmirzaev (16-2) of Uzbekistan, who has won seven fights in a row in ONE over the past two years. ONE has not officially called the bout a title eliminator. MMA Fighting describes it as likely to determine the next man in line for the belt, so the winner should be first in line to face Kholmirzaev next year.

ONE Fight Night 50 lineup

A flyweight submission grappling world title match between champion Diogo Reis and fellow Brazilian Bebeto Oliveira headlines the U.S. primetime card. According to MMA Fighting's updated lineup, the event also includes:

• Diogo Reis vs Bebeto Oliveira (grappling, flyweight title)
• Suablack Tor Pran49 vs Jordan Estupinan (Muay Thai)
• Bampara Kouyate vs Ricardo Bravo (Muay Thai)
• Maurice Abevi vs Dzhabir Dzhabrailov (MMA)
• Selina Flores vs Kana (Muay Thai)
• Antonio Cesar vs Viet Anh Do (MMA)

ONE's official event page also lists a bantamweight kickboxing bout between Ferrari Fairtex and Denis Souza Jr. Kade Ruotolo vs Ok Rae Yoon was reported for this card in October, but it does not appear in MMA Fighting's updated lineup or on ONE's event page as of Thursday. ONE has not commented on that bout's status.

ONE Fight Night 50 takes place on Friday, December 18, U.S. time, which is Saturday morning, December 19, in Bangkok.