No relation to the other American boxer, Ronnie Allen Harris, this Ronnie Harris also fought as a lightweight, and achieved the rare feat of winning the National AAU title three consecutive years – 1966-1968. Harris twice won the Golden Gloves title and was a bronze medalist at the 1967 Pan American Games. Harris attended Kent State University, where he initially studied pre-med. He later embraced Judaism and changed his name to Ronald Mazel Harris. Harris did this after an accident in which he was struck by a car while doing roadwork, and later spoke of a religious awakening he had while in the hospital recovering.
Harris fought as a professional from 1971-82, with a career record of 35 wins (14 by knockout) and 2 losses (1 by knockout). On 5 August 1978 he fought Hugo Corro for the WBA and WBC Middleweight titles, but lost a unanimous decision over 15 rounds in Corro’s hometown of Buenos Aires, Harris’ first loss after 28 victories. Harris won the NABF Middleweight championship in 1979 with a unanimous decision over Edgar Wallace, but lost that title one year later, when he suffered his only career loss by knockout against Sammy NeSmith.