Kevin Rosier was born to a family of farmers in Buffalo, New York. His introduction to combat sports began when he trained in boxing at the Boys & Girls Club in East Aurora, New York. Sensei William James Gallant awarded him his first black belt. At age sixteen, Rosier's massive stature earned him work as a security guard at local clubs in Buffalo. Rosier later became a bodyguard for the likes of Rick James, Billy Idol, and Debbie Harry.Rosier competed in boxing, karate, kickboxing, MMA, and Muay Thai. He was most successful in kick boxing, where he had his most wins by knockouts and technical knockouts in amateur and professional bouts. In 1987, he became the US Kung-Fu Karate National No-Rules Champion. Two years later, he competed in Japan and won to become All-Japan World Champion. The following year, 1990, he won the ISKA North American Super Heavyweight and WKA Super Heavyweight championships.Rosier experienced the difficulties of short-lived promotions, and promoters whom paid little or no money. Undettered, Rosier contacted the organizers of upstart Ultimate Fighting Championship (UFC) in 1993. They recognized him and added him to the event. Rosier fought Zane Frazier in the opening round of UFC 1: The Beginning (1993). He delivered punches and a knee to the face which sent Frazier down. Rosier followed him to the ground with more punches. Frazier recovered,stood up, and get the better of punching exchanges with Rosier's back against the cage for most of the time. Frazier later backed away, and in doing so Rosier knocked him on his back with more punches, and delivered two face stomps to end the fight. Unbeknownst to others at the time, Frazier suffered an asthma attack. Rosier advanced to the second round against Dutch striker Gerard Gordeau. Gordeau targeted Rosier's left leg early, which fell him, then ended the bout with elbows and a foot stomp. Rosier's corner personnel threw in a towel to stop the fight which lasted almost one minute.Rosier's third and last UFC appearance happened at UFC 4: Revenge of the Warriors (1994) He quickly lost by an arm-lock to Joe Charles. Rosier returned to kick-boxing competition that year, winning the WKCC World Superheavyweight Championship. In 1998, Rosier fought Dan Severn in Extremely Challenge. Rosier quickly took the decorated wrestler down, but Severn quickly squeezed himself from underneath, and pushed Rosier on his back, struck his face with a few knees until the referee stopped it. Extreme Challenge's owner Monty Cox would later say that Rosier told him after that he just needed a few weeks training in grappling to beat Severn. Rosier fought Severn a second time that year for Cage Combat, and lost again. Rosier competed twice more under MMA rules. In International Fighting Championships, he first beat Joe Bramante, then later lost to Brad Gabriel on January 22, 2000.A military veteran, Rosier spent many years in between Veterans Affairs hospitals due to health issues, including heart surgery and treatment for post-traumatic stress disorder. After a heart attack, Rosier died on April 14, 2015 in Murfreesboro, Tennessee.
