More than 70,000 tickets have sold for the world heavyweight unification clash between Joseph Parker and Anthony Joshua.

The ticket blitz is believed to have broken the record as the fastest-selling event in history of the Principality Stadium.

The previous record for the stadium was Joshua's last fight against Carlos Takam, which also sold more than 70,000 tickets, but only within the first eight hours.

Joshua's boxing promoter, Eddie Hearn, revealed on Twitter that the tickets had sold out at 1.04pm - just over an hour after they had gone on sale.

Only a limited number of remaining tickets, priced between NZD$500 and NZD$1000, will go on sale next week.