Rico Verhoeven will attempt to do the unthinkable on Saturday night, live on DAZN PPV and DAZN Ultimate, and inflict the first defeat of Oleksandr Usyk's illustrious career.
No one is giving Verhoeven, a kickboxing legend, a chance of beating Usyk, who holds three of the four world heavyweight titles.
But if Verhoeven wins, will he become the new world heavyweight champion?
DAZN News explains the situation surrounding Usyk, his WBA, WBC and IBF world title belts, and what happens if he loses to Verhoeven.
The WBC is the only sanctioning body to allow their belt to be won by Verhoeven if he beats Usyk.
Saturday's fight is a "voluntary defence" by Usyk after his request was granted by the WBC, which allows him to delay facing his mandatory challenger, Agit Kabayel.
This decision by the WBC is a change in their stance.
When Tyson Fury held their version of the world heavyweight title, his fight against Francis Ngannou three years ago was ruled a non-title fight by the WBC who cited the former's efforts to secure an undisputed clash with Usyk as the reason for making the decision.
The WBA have allowed Usyk to defend the belt, but under what they call "strict terms and conditions".
Usyk will be announced as the WBA heavyweight champion on fight night, but the belt itself will not be at stake with Verhoeven not being ranked by the sanctioning body.
If Usyk does lose, his status as champion will be reviewed, and Verhoeven will become eligible to enter the WBA's heavyweight rankings.
The IBF have been the latest sanctioning body to declare its stance on Saturday's fight.
If Usyk is shocked by Verhoeven, the IBF world heavyweight title will become vacant.
But if Usyk wins, the IBF will allow the WBC to call for a mandatory challenger and not name their own for 180 days.
The naming of the IBF's mandatory challenger could be further delayed if the WBA grants Usyk a "special permit" for his first fight after facing Verhoeven.
Oleksandr Usyk puts his unbeaten record on the line against Rico Verhoeven on Saturday, May 23, in front of the Egyptian pyramids, live and exclusive on DAZN. Buy as a one-off PPV or included, along with Zayas vs. Ennis (June 27) PPV, with a DAZN Ultimate Tier subscription.