1920

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.