Regian “The Immortal” Eersel has held the ONE Lightweight Kickboxing World Title six times. He won it first in 2019 — his first piece of gold in ONE Championship — and describes it as a belt with a special place in his career.
On Friday, April 10, he gets his chance to reclaim it when he faces Rungrawee “Legatron” Sitsongpeenong in the main event of The Inner Circle, streaming live from Lumpinee Stadium in Bangkok, Thailand.
The title was stripped from Eersel after he missed weight while hydrated ahead of his trilogy fight with Alexis Nicolas at ONE Fight Night 30. It was a painful and unusual end to an otherwise dominant reign.
He went on to win that fight by unanimous decision. He has since defended his ONE Lightweight Muay Thai World Title with a first-round knockout of George Jarvis at ONE Fight Night 34. Now the 33-year-old Sityodtong Amsterdam fighter arrives with full momentum and a personal mission.
Rungrawee brings a 158-48 career record and one of the most dangerous leg kick arsenals in the division. The southpaw’s ability to punish the right leg of an orthodox opponent is well established. And Eersel has prepared specifically for that threat. He is not expecting a shortcut.
“I anticipate everything. Leg kicks, calf kicks, kicks on my right leg because he stands southpaw, kicks on the inside leg. So I’m training for everything,” Eersel said.
“I think he’s going to kick a lot. I think he’s going to use a mix — one punch, one kick, two punches, one kick, two kicks, stuff like that.”
Regian Eersel breaks down his game plan for Rungrawee Sitsongpeenong
Regian Eersel has always prepared for five rounds, regardless of who stands across from him. That mentality has driven some of the most dominant championship performances in ONE’s lightweight history.
It is the same mentality he carries into The Inner Circle on April 10. He knows he will absorb some of Rungrawee’s kicks across five rounds — that is not a concern. What matters is how he manages distance, counters effectively, and imposes his own rhythm in return.
The belt he is chasing holds more meaning than any other. It was the one that started everything. And he intends to make that clear on Friday night.
“In my mind, I always think we’re going to fight five rounds. Always. I’m not going to think, ‘Oh, I’m going to beat him in the first round or the second round.’ No. If I see the opening, I will go for it, of course. But I don’t expect a knockout. I expect a full five-round war, a technical war between me and Rungrawee,” Eersel said.
“I hope I get my baby back, my first baby, my first title in ONE Championship. I won it in 2019. So yeah, in 2026 I hope I reclaim it, win it again, and become a double champ again. It has a special place. It was my first title, and I also held it the longest.”