Kenny Bristol kept his unbeaten streak intact when he met Gil Rosario on April 5, 1978 in New York. The lanky Guyanese won on points in a six round contest against Rosario to improve to 6-0. It was the first contest that Bristol was involved in that was not held at the Sunnyside Garden in Queens. The gangly southpaw had turned pro in October 1976 and by July 1979 was crowned Commonwealth junior middleweight champion. He was 27-years-old when challenging Pat Thomas for the Commonwealth title and won the 15-rounder via unanimous points decision.
Bristol would hold on to his unbeaten streak until May 1981. He was 14-0 heading into a fight against Canadian Wayne Caplette. Also a southpaw, Caplette won the 10-rounder by split decision. The return was held five months later and Bristol lost following a disqualification in round four.
By now in the twilight of his career, Bristol would have four more fights, losing three of them. He called it quits in February 1984 following a defeat by then unbeaten James Shuler. During his eight years in the ring Bristol scored 15 victories and five losses. He won one fight by knockout.