Detailed Instructions: In this task, you are given a context paragraph, a question based on that and corresponding answer of a question. Your task is to generate supporting fact/knowledge from context paragraph which helps in answering a given question.
Q: James John "Gentleman Jim" Corbett (September 1, 1866 February 18, 1933) was an American professional boxer and a former World Heavyweight Champion, best known as the man who defeated the great John L. Sullivan. 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. Question: What was the nickname of the reigning, retired heavyweight champion at the time of the Fitzsimmons vs. Sharkey Heavyweight Championship boxing match? Answer: "Gentleman Jim"
A:
James John Gentleman Jim Corbett September 1, 1866 February 18, 1933 was an American professional boxer and a former World Heavyweight Champion, best known as the man who defeated the great John L. Sullivan.