A mixed martial artist died early Saturday following a collapse during a Thai boxing competition in Cicero, Illinois, marking his debut in the sport. Isaac Johnson, 31, was taken to a hospital after the incident at Cicero Stadium on Friday, Nov. 21, 2025, where he was later declared dead.
Johnson collapsed near the conclusion of the third and final round of his heavyweight Thai boxing bout at the Matador Fighter Challenge. At 8:38 p.m., emergency personnel were called to transport the injured fighter from 1909 S. Laramie Ave. in Cicero to Loyola University Medical Center in Maywood, Illinois.
The Chicago, Illinois, resident was pronounced dead at 12:01 a.m. Saturday, according to 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, as stated by the Cook County medical examiner’s office and the Chicago Sun-Times.
Event promoter Joe Goytia announced the fighter’s death via Facebook early Saturday morning. “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.”
According to the promoter, Johnson had cleared the state-required physical examination prior to the fight. The Friday night event was promoted as the ultimate MMA and Thai event, featuring local competitors in high-intensity matches. This marked Johnson’s first foray into Thai boxing competition, although he had prior experience in mixed martial arts.
Medical personnel were present at the venue and provided immediate care before Johnson was transported to the hospital. The incident has led to several investigations. Cicero police are conducting a death investigation into the circumstances surrounding Johnson’s collapse and subsequent death.
Additionally, 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 extended condolences to Johnson’s family and confirmed that the agency would thoroughly review the circumstances surrounding his death 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 young daughter. The news has impacted the local combat sports community, where fighters and organizers have expressed shock and sadness over the outcome of what was meant to be a competitive sporting event.
Combat sports organizations typically mandate fighters to undergo medical examinations before competition, including assessments of cardiovascular health, neurological function, and overall physical fitness. These screenings aim to identify conditions that could pose risks during the intense physical demands of competition. Despite these precautions, rare but serious medical emergencies can still occur during matches.
Cicero Stadium, where the event was held, hosts various sporting and entertainment events in the western suburb of Chicago. The venue has hosted combat sports competitions, wrestling events, and other athletic contests over the years.
As investigators work to determine what caused 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 aiming to ensure fighter safety at future competitions.
The Cook County medical examiner’s office has not provided 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.
