Undefeated kickboxing champion Václav Sivák successfully defended his RFA 70-kilogram title in Žilina by defeating Brandon Fos via third-round technical knockout, extending his professional record to 37 wins and zero losses while simultaneously confirming an upcoming contract with ONE Championship. The victory at RFA 34 in the Žilina Tipsport Arena marked the first of three bouts the fighter scheduled in a span of less than two months.
Following the bout, Sivák credited RFA head Boris Marhanský with helping him recover his motivation after a difficult period away from the sport. Marhanský noted that Sivák has competed in the organization for four years and outlined plans for the champion to split his time between RFA and international competition.
Wou, Sivák zničil Fose ve 3.kole. Totálně mu vypl nohu, předtím i málem na spodek. První dvě kola vyrovnané, ale Sivák klobouček 👏#RFA34 pic.twitter.com/3acBEzAMxn
Title Defense Against Brandon Fos
Facing Enfusion champion and former Tadeáš Růžička conqueror Brandon Fos, Sivák controlled the distance and landed precise combinations across the opening rounds. In the third round, Sivák heavily targeted Fos’s leg with a calf kick and a knee, eventually dropping his opponent and forcing a stoppage as the round ended due to the accumulated damage. The successful title defense brought Sivák’s professional record to 37 wins and zero losses.
Transition to ONE Championship and Remaining 2026 Schedule
Sivák announced on social media that he holds an exclusive contract with ONE Championship beginning in January, which will permit him to continue competing under the RFA banner where he has five fights remaining on his current deal. Marhanský stated that a likely scenario involves alternating appearances between both organizations, with potential future RFA opponents including Mamuka Usubyan and James Condé.
Before his move to the international league takes full effect, Sivák faces two additional commitments before the end of the year: a realfight trilogy bout against Patrik Záděra in Prague on November 27, and a boxing match against Václav Mikulášk at Fight Night Challenge in Bratislava on December 12. Yet, while the multi-organization schedule and international debut are set, questions remain regarding how Sivák’s earnings in the Asian organization will compare to his previous status as one of the highest-paid fighters in the Czech Republic and Slovakia.
