Gennady Golovkin and Sergiy Derevyanchenko will fight for the vacant IBF middleweight world title on October 5 at Madison Square Garden in New York.
The fight comes after Canelo Alvarez was stripped of the IBF title on August 1 due to his failure to finalise a match against mandatory challenger Derevyanchenko (13-1, 10 KOs).
Because Golovkin (39-1-1, 35 KOs), the former champion, was next in the IBF middleweight rankings, he and Derevyanchenko were required to meet.
"Everyone knows that I consider Madison Square Garden as my home away from home and there is nothing better than fighting there again. It is old school," Golovkin said in a statement.
"On October 5, it's going to be a good fight. Every time I enter the ring I try to give my fans the fight they want to see, the show they deserve.
"This will be such a fight. Don't miss it. You will see everything you love in the sport of boxing. See you in New York."
The fighters' camps had been given until September 4 to agree to a fight or the IBF would order a purse bid.
Golovkin reportedly preferred a third fight against Alvarez after their controversial draw in September 2017 and the Kazakh's loss by majority decision in September 2018, but Alvarez refused.
Derevyanchenko, 33, will challenge for the IBF title for the second time, having lost a split decision in October to Daniel Jacobs.
A former unified middleweight champion, Golovkin, 37, is aiming to regain the IBF crown he held for three years. He originally lost that belt in the same fashion as Alvarez because he did not agree a fight with Derevyanchenko last year.