Anthony Joshua will take on Oleksandr Usyk at Tottenham Hotspur Stadium on September 25.
Joshua was set to face fellow Brit Tyson Fury in a huge heavyweight unification bout, but that was derailed when the latter was ordered to face Deontay Wilder.
That resulted in the WBO stepping in to order Joshua to face his mandatory challenger, Usyk, and a date and venue have been confirmed by promoter Eddie Hearn.
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Taking to Twitter, Hearn wrote: “Olympic Gold v Olympic Gold, Unified World Heavyweight Champion v Undisputed World Cruiserweight champion.
"The belts go up in the air in front of over 60,000 at the new Tottenham Hotspur Stadium Sept 25!!”
Usyk is unbeaten in 18 fights, and successfully stepped up to heavyweight after slicing through the cruiserweight ranks.
The 34-year-old has beaten Chazz Witherspoon and Dereck Chisora since stepping up to heavyweight, but it will be a rise in class again against Joshua.
Joshua is looking forward to taking on an opponent who is a real danger, and could derail plans for a superfight with Fury next year.
“The date is set and we are fully locked in,” Joshua said. “September 25, Tottenham Hotspur Stadium, I put it all on the line again and it’s time to defend my crown.
“We are two Olympic Gold medallists who have fought our way to the top and never avoided challenges.
“The stadium is exceptional, the atmosphere will be electric, I’m honoured to be the first person to fight in such an awe-inspiring venue.
“The stage is set and I am ready to handle business.”
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