Tyson Fury, boxing's lineal heavyweight champion, and Francis Ngannou, the former UFC heavyweight champion, will fight Oct. 28 in Riyadh, Saudi Arabia.
The announcement clarified that the fight will take place in a regulation boxing ring under boxing rules, including three ringside judges using the 10-point must system.
What remains unclear is the number of rounds, whether Fury's WBC heavyweight title will be on the line, and whether the fight will count toward their professional boxing records.
"I can't wait to get back out there under the lights," Fury said in a statement. "I'm looking forward to showing the world that The Gypsy King is the greatest fighter of his generation in an epic battle with another master of his craft."
"My dream was always to box, and to box the best," Ngannou said in his statement. "After becoming the undisputed MMA Heavyweight Champion, this is my opportunity to make that dream come true and cement my position as the baddest man on the planet."
Fury and Ngannou teased a future meeting in April 2022, sharing the ring after Fury's sixth-round TKO victory over Dillian Whyte in London to retain his WBC heavyweight title.
"Big Francis Ngannou is here today," Fury said at the time. "He's on my hit list in an exhibition fight, however he wants it: in a cage, in a boxing ring, boxing gloves, UFC gloves, we can make it happen. I think everyone wants to see it. He's a monster of a guy, I'm a monster of a guy, so it will be a clash of the titans for sure."
The 34-year-old Englishman returned for a trilogy battle with Derek Chisora in December, a 10th-round stoppage win to retain the top spot in ESPN's heavyweight rankings.
Fury (33-0-1, 24 KOs) was in talks to meet Oleksandr Usyk for the undisputed heavyweight championship in April at London's Wembley Stadium, but negotiations collapsed in March.
Now, ESPN's No. 7 pound-for-pound boxer will meet one of the most recognizable names in combat sports in a star-studded event in the Middle East.
Ngannou (20-3-3 MMA record) last competed in January 2022, when he retained his UFC heavyweight championship with a unanimous-decision victory over Ciryl Gane at UFC 270. That turned out to be Ngannou's final bout in the Octagon.
After he couldn't reach terms on a contract extension with the UFC, Ngannou parted ways with the MMA organization in January. Now, he's set to make his boxing debut, realizing a lifelong dream he set out to accomplish when he fled Cameroon for France at age 26.
Ngannou, 36, underwent surgery in March to repair his MCL and ACL. Two months later, he signed a deal with the PFL that allowed him to box as well.
"My next step has to be boxing," Ngannou told ESPN's Brett Okamoto in March. "I want to do one boxing match first, and then maybe go back to MMA because I still enjoy MMA. I want to do a couple of fights in boxing. We are working on some stuff, and hopefully in a month or two I will be able to come out with an announcement on potential fight dates and locations.
"It's taking a little longer than I expected, but it's coming along. Big things come with time."