When Archie Moore was being promoted as World Heavyweight Champion for the period between Rocky Marciano's retirement and Floyd Patterson beating Moore for the legitimate title.

Some info on Moore's opponent James J Parker who Moore fought for the "Heavyweight Championship of the World", with Moore billed as champion, in July 1956 from a Canadian press article...

"A heavyweight boxing champion, he fought the last bare-knuckle boxing match in Canada.

But “The Barrie Bomber” was also known for his soft side, as a loving husband and father.

The thunderous, right-hand punches and ferocious bouts of James Parker, won’t soon be forgotten in the boxing world.

At a hulking 6-4, 355 lbs. at the peak of his career, Parker was once introduced at Madison Square Gardens in New York as “the hardest-hitting heavyweight in history.” Parker, an inductee of the Canadian Boxing Hall of Fame, fought his final bout in 1958 following a 9-year professional career.

Former world heavyweight champion Tommy Burns, after he won the world heavyweight title, fought two men in one night and both bouts were billed as for the world heavyweight title...James J Walker and Jim O'Brien...boxrec states neither opponent had won a bout before their fights with burns that night.
and...Burns, defended his title twice in 88 seconds...once against Bill Squires (with James J Jeffries as referee) and once in Dublin, on St Patricks Day..against Jem Roache...the only time a world heavyweight fight was staged in Ireland.