Question: What was the unofficial name of the event that caused the man who defeated the great John L. Sullivan to rescind his retirement after hearing of the outcome?
Sentence (from "James J. Corbett"): 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.
Relevant evidence: Yes