Bellator MMA bantamweight champion Darrion Caldwell will face Rizin Fighting Federation's Kyoji Horiguchi in a cross-promotional arrangement on Dec. 31 in Saitama, Japan, the two promotions announced Wednesday.
Caldwell (13-1) and Horiguchi (25-2) will compete for Rizin's inaugural 135-pound championship. Caldwell's Bellator title will not be on the line.
"Bellator wants to support Rizin, and by sending our bantamweight champion to compete during their New Year's Eve event, we look forward to this leading toward more collaboration between the two promotions in 2019," Bellator president Scott Coker said in a released statement.
"I want to wish Darrion luck in his quest to prove he is the best 135-pound fighter on the planet."
The two promotions have shared talent before, including heavyweight Fedor Emelianenko and light heavyweight Muhammed "King Mo" Lawal.
Caldwell, of Rahway, New Jersey, is a former NCAA wrestling champion at North Carolina State University. He is riding a four-fight win streak.
Horiguchi, of Japan, is a former UFC flyweight title challenger, who has won 10 consecutive bouts since losing to Demetrious Johnson in 2015. He trains out of American Top Team in Coconut Creek, Florida.
Rizin's New Year's Eve event is supposed to feature retired boxer Floyd Mayweather in an exhibition match against Japanese kickboxer Tenshin Nasukawa.