In a dramatic headline fight at Oktagon 81 in Prague, one of European MMA’s most dynamic heavyweight champions delivered a statement performance, stunning a former UFC standout and reminding the global fight world that top-level talent thrives well beyond the Octagon.

The event, held at the O₂ Arena on December 28, 2025, featured a heavyweight title clash that pitted reigning two-division champion Will Fleury against Slovak contender Martin Buday. The matchup carried layers of intrigue: Buday had recently left the UFC despite an impressive record, and Fleury was defending the heavyweight crown he had captured earlier in the year. What unfolded inside the cage was swift, decisive, and one-sided.

From the opening bell, Fleury moved with confidence and aggression. A seasoned veteran in multiple major promotions before joining Oktagon MMA, the Irish fighter showcased a blend of striking precision and fight IQ that proved too much for Buday on this night. Within the first round, Fleury landed a powerful counter left that dropped Buday, immediately shifting momentum entirely in the champion’s favor. As Buday attempted to recover, Fleury pushed forward with relentless pressure, forcing the referee to step in and halt the contest as Buday fell for a second time under a barrage of strikes.

The knockout victory — quick, emphatic, and unambiguous — secured Fleury’s successful defense of the Oktagon heavyweight title and extended his dominant run under the promotional banner. Already a double champion at light heavyweight and heavyweight, Fleury now stands tall as one of the most accomplished fighters in Oktagon history, his unbeaten string with the promotion continuing to grow. His performance in Prague underscored his reputation as a force in international MMA, combining refined stand-up, strategic acumen, and the capacity to finish fights decisively.

For Buday, the night marked his first loss under the Oktagon flag and a sobering turn in what had been a rising trajectory. The Slovak heavyweight entered the fight with strong momentum, having reeled off multiple wins since rejoining the European promotion after departing the UFC. His career previously included a noteworthy run in the UFC, where he compiled an impressive 7-1 record — a level of success that usually anchors fighters firmly with the world’s most visible MMA brand. Despite that record, the UFC opted not to re-sign him following his latest victory, a decision that surprised many observers given his recent success inside the Octagon.

Rather than souring on his UFC exit, Buday chose to return to Oktagon MMA, a promotion where he had experienced early career success and familiarity. There, he quickly positioned himself for a shot at regaining the heavyweight title. His debut as a challenger against Fleury had the potential to elevate his profile and serve as a springboard back to the world stage. Instead, he ran into a champion operating at peak form.

The result has significant implications for both fighters’ careers. For Fleury, it reinforces his status as a dominant champion in Europe, potentially increasing his visibility and desirability across the global MMA scene. A string of strong performances in Oktagon could put him on the radar of larger international organizations or set the stage for high-profile crossover bouts. Within Oktagon itself, Fleury’s momentum makes him a central figure in the promotion’s narrative going into 2026, with fans and analysts alike curious to see who — if anyone — can stand toe-to-toe with him.

Buday’s story, meanwhile, remains compelling despite the loss. His departure from the UFC on a strong record showed that even fighters with winning resumes are not immune to contract decisions shaped by broader strategic considerations. With multiple promotions reportedly expressing interest after his release, Buday chose a familiar environment where he could immediately compete for a title. While this particular night did not go his way, the heavyweight contender has already demonstrated resilience and competitive quality throughout his career. At only 34 years old, there is potential for further evolution, growth, and perhaps opportunities in other organizations or future Oktagon showdowns.

Beyond the main event, Oktagon 81 delivered a stacked card featuring several other notable matchups, including a flyweight title fight and multiple bouts involving established regional talents. The event served as the culmination of Oktagon’s 2025 calendar, offering fans a year-end spectacle rich with memorable moments and championship implications.

The swift and decisive nature of Fleury’s victory became the defining highlight of the evening — a moment that will likely be replayed across MMA circles as an example of how quickly elite fighters can dominate at the championship level. With both fighters now moving forward in different directions — one consolidating his legacy, the other regrouping after a tough setback — the heavyweight landscape in international MMA remains dynamic and unpredictable.

As the sport continues to globalize and fighters find success across multiple promotions, performances like this remind fans that elite competition does not reside exclusively within one organization. Champions can emerge, flourish, and command attention wherever they compete, and the paths fighters take — whether in the UFC, Oktagon, or beyond — contribute to the vibrant, interconnected world of mixed martial arts.