In a rare sight for combat sports fans, UFC legend Demetrious "Mighty Mouse" Johnson was forced to tap to a kneebar submission at the 2025 IBJJF World Masters Championships, marking one of the few times the former flyweight champion has been submitted in competition.

The incident occurred during Johnson's black belt division match, where his opponent Kako managed to secure the kneebar in the final minute of their contest. Despite being ahead on points, Johnson found himself caught in the submission hold and was ultimately forced to tap when the pressure became too intense.

"I felt about one or two pops," Johnson revealed after the match, indicating that the submission had caused some damage to his knee joint. The concerning sound of the "pops" highlighted just how tight and effective the kneebar had become before Johnson made the decision to submit.

This submission loss comes as Johnson continues to pursue excellence in Brazilian Jiu-Jitsu alongside his legendary MMA career. The 38-year-old has been actively competing in BJJ tournaments, having previously captured gold at the 2023 IBJJF World Masters as a brown belt before earning his black belt promotion.

Johnson's journey in Brazilian Jiu-Jitsu has been closely watched by fans who rarely saw him in vulnerable positions during his dominant UFC flyweight title reign. His willingness to compete against high-level grapplers in their own arena demonstrates the competitive spirit that made him one of the greatest pound-for-pound fighters in MMA history.

The kneebar submission serves as a reminder of the technical prowess required in high-level Brazilian Jiu-Jitsu competition, where even elite MMA fighters can find themselves caught by specialists in the art. Johnson's experience at the World Masters, despite the loss, continues to showcase his dedication to martial arts excellence beyond just mixed martial arts.

For many fans, seeing Johnson tap out is indeed a rare occurrence, making this moment particularly notable in the combat sports world. The former UFC champion's willingness to put himself in these challenging positions speaks to his character as a true martial artist who continuously seeks to improve his skills across all disciplines.