Kyokushin is often referred to as “Muay Thai in a Gi”. The training is similar enough, that Kyokushin fighters often fit in almost seamlessly within a Muay Thai setting.
We also kicked their ass in the Karate vs Muay Thai extravaganza in the 60s featuring their TOP THREE Thai fighters vs what was supposed to be our top three Kyokushin fighters.
However, one of the Kyo fighters got injured (thanks to the Thai camp delaying the fight for weeks, after they witnessed the power and heard the impacts of the Kyokushin camp’s training(long, separate story)...and had to be replaced by one of the instructors who, at the time, was well beyond recommended fighting age.
The battle proceeded, though, and we won best out of 3(the old instructor lost his fight). Whole thing was under Muay Thai rules(meaning they were allowed to clench, knee, and elbow), it was IN Thailand, and it was against their top 3 fighters.
I love training with Muay Thai camps. It never fails, their surprise when they spar with me and I bang hard with zero retreat, and my roundhouse leg kicks feel like baseball bats like theirs. I enjoy watching their body language change, watching that newfound respect for Kyokushin envelope them mid-round lol.