Ok Rae Yoon and Alibeg Rasulov will now duke out for the ONE interim lightweight MMA world title in the main event of ONE Fight Night 23.
The victor will go on to face divisional king Christian Lee in a unification contest at a later date.
The lightweight scrap, originally set to precede the main event, was elevated to the headliner showdown of the July 5 bill after Jackie Buntan withdrew from her inaugural ONE strawweight kickboxing world title matchup against Anissa Meksen.
With 26 pounds of gold added to the plot, this already intriguing contest between the South Korean heavy hitter and the Turkish grappling wizard should turn into an even more fiery clash.
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Ok Rae Yoon has been fueled by revenge since losing his lightweight crown to 'The Warrior' at ONE 160 in August 2022.
He kickstarted his comeback arc with a decisive win over Lowen Tynanes at ONE Fight Night 10, and another massive victory over the promotional newcomer will finally earn him the trilogy that he has long been after.
In their first fight, the 33-year-old scored a stunning upset of Lee to walk away as the ONE lightweight world champion after a back-and-forth five-round thriller.
Apart from those wins mentioned above, the Busan native owns notable triumphs over former multiple-time MMA world champions Marat Gafurov and Eddie Alvarez on the global stage.
Having shared the Circle with some big names in the past, the South Korean hopes his experience will pave the way for a 18th career win at ONE Fight Night 23.
That said, it certainly would not come easy if you throw in Rasulov's elite all-around game arsenal.
The 31-year-old debutant has stayed a perfect 14-0 through his career, with 10 of his wins coming by finish.
Backed with raw power and craftiness in both facets of his game, Rasulov should be able to impose his style on Ok early into their ONE Fight Night 23 main event fixture.
Though the Turkish megastar does not have the same big time experience as Ok Rae Yoon, he will be more than ready to blast his way to ONE gold in his promotional bow and a unification war against Lee, who currently reigns as the promotion's lightweight and welterweight MMA world champion.
ONE Fight Night 23 emanates live at U.S. primetime from the Lumpinee Boxing Stadium in Bangkok, Thailand, on Friday, July 5.
North American fans with an active Amazon Prime Video subscription can tune in for free.
Other fights joining Ok Rae Yoon-Alibeg Rasulov at ONE Fight Night 23:
Tye Ruotolo vs Jozef Chen (Submission grappling - 186-pounds catchweight)
Nico Carrillo vs Saemapetch Fairtex (Muay Thai - bantamweight)
Kang Ji Won vs Kirill Grishenko (MMA - heavyweight)
Tatsumitsu Wada vs Xie Wei (MMA - flyweight)
Ali Saldoev vs Black Panther (Muay Thai - flyweight)
Hiroba Minowa vs Jeremy Miado (MMA - strawweight)
Shinji Suzuki vs Stefan Korodi (Muay Thai - bantamweight)