James John "Jim" Corbett (September 1, 1866 – February 18, 1933) was an American professional boxer and a World Heavyweight Champion, best known as the only man who ever defeated the great John L.
Sullivan (hence the "man who beat the man" concept of the championship boxing lineage.) Despite a career spanning only 20 bouts, Corbett faced the best competition his era had to offer; squaring off with a total of 9 fighters who would later be enshrined alongside him in the International Boxing Hall of Fame.
Corbett introduced a truly scientific approach to boxing, in which technique triumphed over brute force, he pioneered the daily boxing training routine and regimen, which, being adopted by other boxers elsewhere, almost intact survived to modern days.
A "big-money fighter," Corbett was one of the first athletes, whose showmanship in and out of the ring was just as good as his boxing abilities, also being arguably the first sports sex symbol of the modern era after the worldwide airing of his championship prizefight versus Robert Fitzsimmons popularized boxing immensely among the female audience, and did so in an era while the prizefighting was illegal in 21 states and still considered among the most infamous crimes against morality.