ONE Championship returns this week with another double-header inside Bangkok, Thailand's Lumpinee Boxing Stadium. After ONE Friday Fights 58 opens the show on Friday night, ONE Fight Night 21: Eersel vs. Nicolas follows on Saturday morning, 6 April.
ONE Fight Night 21 goes down inside "the mecca of Muay Thai" and brings with it a colossal night of fights headlined by two World Title bouts across just as many sports.

While the upper part of the card will garner the attention it deserves, there are several undercard bouts worthy of recognition. Let's take a look at three fights under the radar.
In what will be a barnburner for as long as it lasts, fiery flyweight Muay Thai scrappers Jacob Smith and Denis Puric lock horns as both men take huge momentum into the firefight.
Smith returned after an 18-month layoff last December at ONE Fight Night 17, knocking out #3-ranked flyweight Muay Thai contender Walter Goncalves in one of the biggest comeback stories of the year.
The victory inserted the Liverpool lad into the top five immediately, and he believes a victory over Puric could solidify his championship hopes. But Puric would love to deny him of those dreams.
The Bosnian enters the frame having also knocked out Nguyen Tran Duy Nhat at ONE Fight Night 17. And when he steps into the ring on his birthday this weekend, Puric hopes to extend his winning streak and celebrate turning 39 in emphatic fashion.
Ben Tynan has been one of the most outgoing, charismatic names to debut in ONE's heavyweight MMA division this year. But if he wants to keep the party going, he'll have to topple the durable Duke Didier this weekend.
Tynan arrived last November at ONE Fight Night 16. "Vanilla Thunder" dispatched Kang Ji Won with a third-round knockout after mauling the South Korean. The Canadian has dreams of conquering the weight class, but overcoming a judo and BJJ black belt will be his first priority.
The night will provide an opportunity for Didier to make things right after losing a split decision in his promotional debut at ONE 158. His comeback has been a long time coming, and cementing a win over a surging talent like Tynan would certainly force the division to take notice.
If there's anyone with as much momentum going for him right now as Suablack Tor Pran49, you'll be hard pressed to name him. The Thai striker has been untouchable in the ONE Friday Fights series, and he looks to earn his sixth straight win in the series against Vladimir Kuzmin.
The bantamweight Muay Thai battlers are two of the toughest names in the division. But for
Suablack, another stoppage victory over the gritty Kuzmin would be a huge statement. And for Kuzmin, toppling the formidable Thai would be a big name to add into his resume.
The Russian rides an impressive two-fight winning streak with wins over Fabio Reis and Zafer Sayik. And if he can add Suablack to the list, he'll only move up in ONE Championship.