The reason is honorable.
Tawanchai fractured his leg during a kickboxing bout with China’s Liu Mengyang at ONE Friday Fights 137 in December 2025, a fight that ended by calf kick at 52 seconds. The Thai underwent surgery and entered an extended rehabilitation window. He held onto the belt through the first half of 2026 while his camp assessed the timeline. Tuesday, he stepped aside.
“Winning this belt has been a tremendous honour, and that honour will always remain with me, whether or not I have this belt,” Tawanchai said in a statement released alongside the press conference. “I am voluntarily relinquishing the championship out of respect for the organisation and all the fans.”
He expanded on the decision in a longer statement.
“Every athlete dreams of holding onto their title for as long as possible, and I’m no exception,” he said. “But after taking time to reflect, especially regarding my injury, I am officially announcing that I am vacating my World Championship title today. I want to give the interim champion and the top-ranked contenders the chance to chase their dreams.”
The reign that closes here was one of the more dominant runs the division has produced. Tawanchai took the belt from Petchmorakot Petchyindee by unanimous decision at ONE 161 in September 2022, in a five-round war that established the pattern of the reign to come. Four successful defences followed: Jamal Yusupov, Jo Nattawut, and Superbon Singha Mawynn twice. His most recent Muay Thai appearance came at ONE 170 in January 2025, when he stopped Superbon in the second round of their rematch. Between those points, he built the technical identity that made him one of the most watched featherweight strikers on the planet. Patient, teep-heavy pressure. A left kick thrown from a squared, slightly bladed stance. The willingness to catch a low-line and let opponents walk onto the shin. Losing that from the active division, even temporarily, matters.
Carrillo’s path
The elevation is not a gift. Carrillo (29-4) earned it the hard way.
The Scot joined ONE Championship in April 2023, decimating Furkan Karabag by third-round TKO in his featherweight debut. He then moved down to bantamweight, where he finished Muangthai PK Saenchai, the beloved Elbow Zombie, by second-round TKO to earn a six-figure contract. Wins over former ONE Bantamweight Muay Thai World Champion Nong-O Hama and title challenger Saemapetch Fairtex followed, all by knockout. He moved back up to featherweight for the interim title opportunity, and at ONE Fight Night 40 in February 2026 he outworked Shadow Singha Mawynn across five rounds for a unanimous decision. He also broke Shadow’s jaw during the fight, a detail that only surfaced fully after the doctors got a look.
The interim result was the sort of performance that justified the belt then, and the promotion now. Carrillo built his reputation on volume and pressure at bantamweight before moving up. The step to featherweight raised questions about how his boxing structure would hold against larger frames, particularly against orthodox kickers with reach. Against Shadow, he answered them. He absorbed clean shots, adjusted his level of engagement, and closed the distance often enough to bank rounds in the clinch and against the ropes. When his hands were the answer, he used his hands. When they were not, he used his frame.
“The division can once again be active,” Carrillo said Tuesday. “You can try, you will not succeed.”
His full statement carried the residue of a longer conversation.
“No disrespect to Tawanchai, but it’s about time,” Carrillo said. “At the end of the day, the division needs to stay active and needs a champion defending the belt. I’m glad ONE Championship is doing the right thing. The fans need this. When Tawanchai is fit and ready, he’ll be first in line to fight for the belt again.”
The pressure that got us here
Carrillo’s camp had been making the strip argument publicly for months. Coach JP Gallacher told the Bangkok Post in early July that they were not waiting on Tawanchai. They were waiting on ONE to do the right thing. His public phrasing was direct. No champion in memory, he argued, had been allowed to hold onto a belt that long with no activity and no clear signal of a return.
The organisational path Tuesday chose the middle road. Not a strip. A voluntary vacation, framed by Tawanchai as a gesture of respect, that produces the same practical outcome. The division moves. Carrillo holds the belt. Tawanchai gets the runway to return on his own terms, without having a piece of paperwork used against him publicly.
What comes next
Carrillo’s next assignment is not a title defence. He is scheduled to make his ONE kickboxing debut against Zhou Jiaqiang at ONE Fight Night 46 on August 15 at Lumpinee Stadium in Bangkok. A cross-ruleset booking under kickboxing rules, no clinch work of consequence, no elbows, at the venue that has hosted Muay Thai for generations. Per Gallacher, the bout is a one-off. Carrillo is not making a broader move into kickboxing, and the camp has no plans to chase a second belt in the sport. The fight exists to keep the newly elevated undisputed champion active while the featherweight Muay Thai contender queue sorts itself out.
The stylistic question is straightforward. Carrillo’s clinch and knee game, the equaliser against Shadow in the later rounds, is largely legislated out under kickboxing rules. He will need his hands, his low kick, and his footwork to carry the fight. Zhou is a volume striker who will make him work for every exchange.
When Tawanchai returns, the rematch writes itself. Whether it comes in 2026 or 2027 depends on the shin. Fractures in an active nak muay are not casual injuries. The bone remodels. The confidence to load and drive through a kick takes longer to return than an x-ray suggests. Both fighters are 27. Neither is under pressure from the calendar.
Until then, the belt sits with a fighter who earned the interim version the hard way, then had the top line of the division removed from his path by circumstance rather than combat. Whether that ledger reads as a gift or a promotion is the sort of question the sport will ask throughout Carrillo’s first defence and answer on the night of the rematch.
