In July 1994, Lomulder had his mixed martial arts debut in the Vale TudoJapan event against shoot wrestlerKenji Kawaguchi. The Japanese charged for a takedown, but Lomulder kept himself standing by grabbing the ring ropes and scored multiple strikes on the back of Kawaguchi's head. Kawaguchi eventually took him down, only for Lomulder to answer with legal rabbit punches that forced the wrestler out of the ring. A controversial moment happened when Kawaguchi tried to return to the ring, as the referee didn't stop the action, meaning Lomulder scored soccer kicks and stomps while he did so. The action repeated against the ring ropes, where Lomulder landed multiple elbow strikes to the back of the head and followed with and more soccer kicks and stomps. After a restart, the downed Kawaguchi tried to come back with a kneebar, but Lomulder blocked the technique and landed a heavy kick on the face, leading the referee to stop the match. Lomulder advanced round, which would have pitted him against American kickboxer Bud Smith, but he withdrew from the tournament due to a broken hand. Lomulder's next match in Japan would be for K-1 promotion, where it was hosted a special MMA bout against shootboxing expert Naoyuki Taira. The affair was short, as Taira threw Lomulder to the ground and locked a quick rear naked choke for the tap out. Three years after their first encounter in Vale Tudo Japan, Lomulder and Kawaguchi rematched in the Vale Tudo Japan edition of 1997. This time, the match lasted three rounds, and it saw the shoot wrestlers eventually taking Lomulder down and executing a rear naked choke for the victory. It would be Lomulder's last MMA fight.
After retirement
Today Jan Lomulder is a Muay Thai trainer at a gym in Coevorden, Netherlands. He also gives private training sessions for competitive fighters. Recently Jan Lomulder trained former sumo wrestlerWakakirin Shinichifrom Japan. On 13 February 2016 Jan Lomulder and his wife Samantha Lomulder organized a fighting tournament called Rising Sun Muay Thai Gala 2.0. For many years now Jan Lomulder has worked as a referee in kickboxing en muay thai matches. On 26 June 2010, Lomulder returned to kickboxing at Fight 058 in Leeuwarden, Netherlands where he faced old foe Andre Mannaart. After five hard rounds, Lomulder won by decision to Andre Mannaart. On December 10, 2011 Jan Lomulder fought former champ Dervis Akdeniz for the W.F.C.A. world title 2011 at the 2 The Maxx tournament in Hoogeveen. Jan Lomulder won the match and became the 2011 World Champion W.F.C.A. 40 +
