Buster Mathis

Buster Mathis (June 11, 1943 – September 6, 1995) was an American boxer.
Career.
Mathis had a successful career as an amateur heavyweight boxer. He qualified for a spot in the 1964 Tokyo Olympics, but had to withdraw due to an injury. He was replaced in the tournament by Joe Frazier who went on to win the gold medal.
Mathis turned professional in June 1965 with a second round knockout victory over Bob Maynard. He went on to win his next 22 contests as well and qualified for a shot at the New York State Athletic Commission World Heavyweight Title, which had become vacant after Muhammad Ali was stripped of the title for refusing to be drafted into the United States Army.
The title fight was held on March 4, 1968, in New York's Madison Square Garden against 'smoking' Joe Frazier, his old rival. Frazier won by 11th-round knockout. 
Buster Mathis continued to fight in the following years, outpointing George Chuvalo, but losing on points to Jerry Quarry - a fight Mathis was favoured to win. Mathis retired after losing to Quarry in 1969, but returned in 1971 to box Muhammad Ali for the NABF belt, losing on points over 12 rounds. Ali was later criticized for not finishing Mathis in the final rounds of the fight.
After Mathis was knocked out in just two rounds in September 1972 by Ron Lyle, he retired for good.
Retirement.
A 1980 "Sports Illustrated" article featured interviews with Mathis and many of Muhammad Ali's other opponents. It reported Mathis worked in the trucking business after he retired from the ring. 
Mathis had various health problems in later years, including two strokes, a heart attack, and kidney failure. He died of heart failure at age 52. His son Buster Mathis Jr. became a professional boxer, and fought Mike Tyson in 1995.