Stamp Fairtex and the Three Belts: A Career Told in Dates

Stamp Fairtex was born Nadthawan Panthong on November 16, 1997, in Rayong, a province on the Gulf of Thailand better known to foreigners for its beaches than for its fighters. She began Muay Thai as a small child. The story usually told is that she started because other children bullied her at school, and that she won her first fight with knees. The details vary from one telling to the next. The shape does not.

What follows is a record. A fighter’s career looks like a rise when you watch the highlight reel, and like something closer to weather when you line up the dates. Stamp’s career rewards the second method.

The Gym in Pattaya

At around eighteen she moved to Fairtex, the large training camp in Pattaya, and took the gym’s name as her surname, as Thai fighters do. Pattaya is a city built for visitors. Fairtex sits inside that city and runs on a different clock: early runs, pad rounds, clinch work until the light goes flat in the afternoon.

She had already been a stadium champion in the Eastern provinces. In 2017 she won the Thepprasit Stadium title at light flyweight, Thepprasit being the Pattaya venue where tourists and locals sit a few feet apart and the gamblers do not look at the tourists at all. Women’s Muay Thai in Thailand at that time was a smaller world with fewer purses and fewer opponents, and the big Bangkok stadiums kept their traditions. For the long background on those traditions, including the old rope taboo that decided who could step into the ring, the history is worth reading slowly.

ONE Championship signed her in 2018. The company was building a women’s atomweight roster (the 115-pound class, or 52.2 kilograms) across several sports at once. Stamp would end up competing in all of them.

Stamp Fairtex, Year by Year

The belts came quickly and then went, one after another, and then came back in a different form. A table does this better than paragraphs.

Two things stand out. Within roughly eighteen months, between late 2018 and early 2019, she held world titles in two striking sports simultaneously. By the end of 2020 she held neither. The year 2020 was unkind to many fighters, and to her it was precise: February took one belt, August took the other.

The Striker Who Learned to Wrestle

Stamp’s MMA debut had lasted 19 seconds, and a debut like that tells you almost nothing. A head kick against an opponent who did not see it coming says more about the opponent. The real education came later, on the mat, in the parts of the sport that a Muay Thai upbringing does not cover.

Muay Thai fighters who cross into MMA carry certain habits with them. They stand tall. They check kicks. They expect the clinch to end in a knee or a sweep, and in MMA a clinch can end with their back on the canvas. Some adjust, some do not, and the ones who build careers in the cage tend to be the ones who accept, early, that the ground is a separate country with its own language. The pattern repeats across promotions, and the list of fighters who have made it work, catalogued in this piece on Muay Thai in the UFC, is shorter than the list of those who tried.

Stamp lost to Alyona Rassohyna in January 2021, caught in a guillotine in the closing seconds of the third round. The first MMA loss of her career came with almost no time left on the clock. Then she entered the ONE Women’s Atomweight World Grand Prix and went through the bracket:

1. Alyona Rassohyna, September 3, 2021, split decision. The rematch, and the first sign that the earlier loss had been studied.
2. Julie Mezabarba, October 29, 2021, unanimous decision.
3. Ritu Phogat, December 3, 2021, armbar in the final.

The last result is the one to sit with. Phogat came from freestyle wrestling, from an Indian wrestling family known well beyond the sport. A Muay Thai fighter from Rayong finished her with a submission. Nobody who watched Stamp in 2018 would have predicted that.

Singapore, March 2022

The Grand Prix earned her a shot at Angela Lee, the atomweight MMA champion, at ONE X in Singapore. Lee was the division’s reference point: a grappler, a champion since 2016, a fighter who had been doing this in a cage for years longer than Stamp had.

The fight lasted into the second round. Lee took her down and finished with a rear-naked choke.

People sometimes describe a loss like that as a lesson. The description is too tidy. What the fight showed was a gap, measurable in years of mat time, and a gap of that kind closes only with more years of mat time. Stamp went back to Pattaya.

What Changed Between 2022 and 2023

She won three times in the cage after the Lee loss. Against Jihin Radzuan in October 2022 she won on the scorecards. Against Alyse Anderson in 2023 she won with a kick to the body, which is to say she won with the oldest weapon she had, set up by the threat of the newer ones. An opponent who fears the takedown drops her hands differently. The body opens.

Lee announced her retirement in 2023. The interim title bout Stamp had been booked into against Ham Seo-hee, the veteran from South Korea, became a fight for the undisputed belt. At ONE Fight Night 14 in Singapore, on September 30, 2023, Stamp stopped Ham with punches to the body in the third round.

With that result she became the first athlete to hold ONE world titles in Muay Thai, kickboxing, and MMA. The phrase “three-sport” gets attached to her name so often now that it has started to sound like a slogan. On the record it amounts to three separate belts won across five years, against specialists in each sport, with two of those belts lost along the way.

The Knee

In May 2024 she tore the meniscus in her knee. The injury required surgery, and the recovery did not follow the schedule anyone wanted.

A unification bout against Denice Zamboanga, the interim champion from the Philippines, was planned for 2025. The recovery suffered another setback. In May 2025 Stamp withdrew and agreed to relinquish the atomweight MMA title, and Zamboanga was elevated to undisputed champion. On June 23, 2026, Zamboanga herself vacated the belt after the birth of her first child. As of late September 2026, the division that Stamp once held is open.

Knee injuries do something particular to strikers. The kick is thrown from the standing leg as much as from the kicking one, and a fighter who does not trust the standing leg throws with half her weight. Stamp said as much after her 2026 comeback win, admitting she could not pull the trigger on her kicks. She also said her main trainer had fallen ill and could not work her corner that night.

Back at Lumpinee

Her first fight back, in November 2025 at ONE 173 in Tokyo, was a kickboxing bout against Kana Morimoto, a four-time K-1 champion. Kana won a unanimous decision. The date was Stamp’s twenty-eighth birthday.

The next two fights took place at Lumpinee Stadium in Bangkok, the most storied ring in Muay Thai, and for most of its history a ring where women did not compete. The setting carries its own weight. The women now headlining cards there are fighting inside the same ropes that were once off limits to them, and Stamp is among the most famous of them. If you want the wider view of who else is changing the sport, a good starting point is this guide to women’s Muay Thai and the fighters profiled there.

On June 26, 2026, at The Inner Circle 20, she beat Cynthia Flores of Mexico by split decision. It was close and it was not pretty, and she said afterward that she had given everything she had.

On September 4, 2026, she headlined ONE Fight Night 47 against Selina Flores, the two-time WBC Muay Thai world champion known as “Teep Queen.” Stamp won again by split decision. ONE’s own report described a fighter who looked more willing to commit: body kicks, knees in the clinch, a spinning back elbow. Her striking record moved to 66 wins and 18 losses. She spoke afterward about returning to MMA.

What to Watch For Next

A few questions will decide the next chapter, and none of them has an answer yet.

• The kick. Watch the first round of her next fight for the rear body kick. If she throws it early and with full hip turn, the knee is no longer in her head.
• The sport. She has said her goal is to win back the atomweight MMA title. With the belt vacant, the path there may be shorter than it looked a year ago, or it may run through a tournament or an interim bout.
• The ground. Two years out of the cage is a long time for grappling timing. Her takedown defense in a first MMA fight back will tell you more than any interview.
• The age. She turns 29 in November 2026. For an atomweight with a surgically repaired knee and more than eighty professional striking bouts behind her, 29 is not young. She has named three or four fights in 2026 as her own target.

For anyone training Muay Thai, her career offers one plain practical point. Stamp did not become an MMA champion by abandoning what she knew. She kept the kicks and the clinch, spent years adding the wrestling underneath them, and won her title with a body shot. When you cross-train, keep your base sport sharp while you learn the new one, because the old weapons are what make the new skills dangerous.