Simsri Stops Vicelles in Two to Retain IBF Light Flyweight Title
Thailand's Thanongsak Simsri knocked Mark Vicelles down twice with right hands and stopped him in the second round in Fuji City, Japan, on 26 September 2026. Mandatory challenger Regie Suganob is next in line.
Thanongsak Simsri needed less than two rounds to keep his IBF light flyweight title. On Saturday, 26 September 2026, the Thai champion floored Filipino challenger Mark Vicelles twice with straight right hands at Fujisan Messe in Fuji City, Shizuoka, and the referee stopped it in the second round. It was his second straight early finish as champion, and it leaves him with a mandatory defence already on the calendar.
Two Right Hands in Round Two at Fujisan Messe
Vicelles, a southpaw based in Japan, opened at a fast pace, and Fightnews ringside reporter Joe Koizumi gave him the first round for his aggression. The second round turned quickly. Simsri landed a straight right that put Vicelles down. When the challenger rose, another right sent him to the canvas again about half a minute later, by The Ring's account. Simsri then landed a flurry of heavy shots at close range, and Japanese referee Koji Tanaka stepped in.
The reports give slightly different stoppage times. Fightnews and The Freeman in Cebu record 2:05 of round two, while The Ring has 2:10. Simsri's record moved to 41-1 with 36 knockouts. Vicelles dropped to 21-4-1. Ohashi Promotions and Suruga Danji Promotions staged the card. In the chief support bout, Filipino Pete Apolinar won the vacant WBO Asia Pacific junior lightweight title, stopping Shunpei Ohata in the ninth round.
From Sisaket Muay Thai to a World Title in Tokyo
Simsri was born on 17 June 2000 in Sisaket Province in northeastern Thailand and is nicknamed "The Black Wolf." He began in Muay Thai. He moved to Bangkok and switched to boxing at 19, and his professional debut in June 2018 ended with a first-round stoppage.
His only loss so far came on 10 September 2022, when former WBC champion Masamichi Yabuki stopped him in seven rounds. He won the vacant IBF 108-pound title on 19 June 2025 at Ota City General Gymnasium in Tokyo, beating Christian Araneta on a split decision after getting up from a third-round knockdown. In his first defence, on 13 April 2026 at Korakuen Hall, he stopped Mexico's Sergio Mendoza in two rounds. The Vicelles fight ended in the same round.
Vicelles and a Long Road Through the Regional Ranks
Ronnie Mark Vicelles, known as "Rasta Mac," was born in 1995 in Lebak, Sultan Kudarat, in the southern Philippines. He turned professional in 2016 and won his first eleven fights. Along the way he won the WBA Asia South title in 2019, and earlier in 2026 he won the vacant OPBF light flyweight belt. His career has also had setbacks. He lost a technical decision to Regie Suganob in 2023 and was stopped by Kosuke Tomioka in 2025. Fuji was his first world title fight, and it was over in about five minutes of ring time.
Suganob, Kira and Iwata Wait at 108 Pounds
Simsri's next opponent is largely decided. Regie Suganob of the PMI Bohol Boxing Stable, who is 19-1 with 8 knockouts, earned the IBF mandatory position when he stopped South Africa's Sivenathi Nontshinga in five rounds in Tagbilaran City on 12 September. The Freeman reports that the IBF set 31 January 2027 as the deadline for the Simsri-Suganob fight. Because Suganob has already beaten Vicelles, the matchup will draw comparisons with Saturday's result.
The champion has also said he wants bigger fights. The Ring reported that Simsri wants unification bouts at 108 pounds, not routine defences against underdogs. The other light flyweight champions include WBA titleholder Daiya Kira, who is 5-0 with 4 knockouts, and WBC champion Shokichi Iwata, who is 17-2 with 14 knockouts. For now, the mandatory against Suganob comes first.
Sources
- Simsri stops Vicelles in 2nd to retain IBF 108-pound world title, The Ring (Mosope Ominiyi), September 2026
- Simsri keeps IBF light fly crown with 2nd round TKO of Vicelles, trains sights on Suganob next, The Freeman / Philstar (Emmanuel B. Villaruel), 28 September 2026
- Simsri Halts Vicelles In Two, Keeps IBF 108lb Belt, Fightnews.com (Joe Koizumi), 27 September 2026
- Thanongsak Simsri, Wikipedia, accessed 3 October 2026
- Mark Vicelles, Wikipedia, accessed 3 October 2026
