July 1971 (George Foreman), August 1971, December 1971 (Ken Buchanan), Januaru 1972 (Joe Frazier), March 1972, May 1972 (Floyd Patterson/Oscar Bonavena), June 1972, September 1972 (Carlos Monzon/Jean Claude Bouttier), February 1973 (Ron Lyle/Luiz Pires)