A mixed martial arts fighter, Isaac Johnson, passed away early Saturday after collapsing during a Thai boxing match in the suburbs of Chicago, Illinois. This match marked his inaugural participation in the sport. The 31-year-old was taken to a hospital following the incident at Cicero Stadium on Friday, November 21, 2025, where he was later declared dead.
Johnson collapsed near the conclusion of the third and final round of his heavyweight Thai boxing match at the Matador Fighter Challenge. Emergency responders were called at 8:38 p.m. to transport the injured fighter from the venue at 1909 S. Laramie Ave. in Cicero, Illinois, to Loyola University Medical Center in Maywood, Illinois.
The Chicago resident was pronounced dead at 12:01 a.m. on Saturday, as reported by the Cook County medical examiner’s office. An autopsy conducted on Saturday did not determine the cause or manner of death, with results pending further investigation, according to the Cook County medical examiner’s office and the Chicago Sun-Times.
Event promoter Joe Goytia announced the fighter’s death on Facebook in the early hours of Saturday. “This is a post I hoped to never make, last night one of the fighters in our event Isaac Johnson collapsed towards end of his fight,” he wrote. “Medical attention was given by medical staff on hand and he was transported to the hospital. I was then informed at around 130 am this morning that he didn’t make it.”
The promoter noted that Johnson had passed the state-mandated physical examination before the fight. The Friday evening event was promoted as the ultimate MMA and Thai boxing event, showcasing local competitors in intense matches. This was Johnson’s first foray into Thai boxing competition, although he had previous experience in mixed martial arts.
Medical personnel were on-site and provided immediate care before Johnson was transported to the hospital. The incident has led to multiple investigations. Cicero police are conducting a death investigation into the circumstances surrounding Johnson’s collapse and death.
Moreover, the Illinois Department of Financial and Professional Regulations, which oversees combat sports licensing and regulation in the state, is reviewing the incident.
A spokesperson for the department conveyed condolences to Johnson’s family and confirmed that the agency would thoroughly review the circumstances surrounding his passing after the amateur Muay Thai bout. The state regulatory body ensures that combat sports events comply with safety standards and that fighters meet medical requirements before competing.
Johnson is survived by his wife and a young daughter. The local combat sports community has expressed shock and sadness over the outcome of an event intended to be a competitive sporting occasion.
Typically, combat sports organizations require fighters to undergo medical examinations before competition. These assessments include evaluations of cardiovascular health, neurological function, and overall physical fitness, aiming to identify conditions that could endanger fighters during the physical demands of competition. Despite these precautions, rare but serious medical emergencies can still arise during matches.
Cicero Stadium, where the event took place, hosts various sporting and entertainment events in the western suburbs of Chicago. Over the years, the venue has hosted combat sports competitions, wrestling events, and other athletic contests.
As investigators work to understand the cause of Johnson’s collapse and death, the combat sports community awaits the results of the autopsy and official reports. The findings may provide crucial information not only for Johnson’s family and friends seeking answers but also for regulators and event organizers working to ensure fighter safety at future competitions.
The Cook County medical examiner’s office has not given a timeline for when autopsy results will be released. Such examinations can take weeks or months to complete as medical professionals conduct thorough analyses and await toxicology and other specialized test results.
