A mixed martial arts wrestler dies after collapsing in the ring sports

American mixed martial arts wrestler Isaac Johnson died this weekend after sustaining serious injuries during a fight in the United States.

Isaac Johnson lost his life as a result of injuries he sustained during a fight in the “Matador Fighter Challenge” event at Cicero Arena, in the suburbs of Chicago, on Friday, November 21.

MMA Fighter Isaac Johnson Dead at 31 After Fight pic.twitter.com/5pHNlDzLOr

— TMZ (@TMZ) November 23, 2025

During the third round In the heavyweight Muay Thai fight against Mario Aleksandrovsky, The 31-year-old American collapsed and was immediately taken to hospital, according to event organizer Joe Goitia.

Johnson died a few hours later at Loyola University Medical Center, and the results of the autopsy have not yet been announced.

An investigation was opened to determine the exact cause of death and verify compliance with safety protocols at the event held in Chicago.

“I have no words to express how I feel right now,” Goitia wrote in a Facebook post. “I extend my deepest condolences to his family, friends and teammates.”

The tragedy forms part of a horrific series of deaths in combat sports in 2025, including the deaths of two 28-year-old Japanese boxers on August 2 in Tokyo.

The World Boxing Organization (WBO) expressed its “deep sadness” over these losses and stated on social media that Shigetoshi Kotari “died as a result of injuries he sustained during his title fight on August 2.”