Possibly Lennox Lewis .... I have copied following extract from website :-
By Paul Upham: It's not every day that you get to sit down for lunch with someone once regarded the undisputed heavyweight boxing champion of the world. The way heavyweight boxing is going today with no one universally recognised champion, Lennox Lewis could be the last undisputed champion for a very long time. While he retired in February 2004, many fans still regard him as the real king of the heavyweight division.