VASYL LOMACHENKO and Teofimo Lopez will fight in an October 17 unification bout.
The lightweight pair had been in line to box in April, until the coronavirus pandemic KO’d the clash.
And despite the delay, the champions have agreed terms to fight next month.
Lomachenko, 32, will put up his WBC Franchise, WBA and WBO belts while Lopez, 23, defends his IBF title.
Top Rank uploaded pictures on Twitter with duo signing on the dotted line before confirming the fight was officially sealed.
Lomachenko said: “Lopez can talk all he wants. He’s very good at talking.
“He has done nothing but say my name for the past two years. I am a fighter, and my goal is to win another world title.
“Good for Teofimo. When we fight in Las Vegas, he will eat my punches and his words.
“I will be the better man, and four world titles will come home with me to Ukraine.”
Lopez said: “I will beat up Lomachenko and take his belts. Simple as that. I’m coming to Las Vegas to make history.
“I don’t like the guy, and I’m going to have fun as Lomachenko’s face is beaten and marked up by my hands.
“The takeover is here, and the reign of Lomachenko, the little diva, is coming to an end.”
The crisis has caused the unification to be moved from pay-per-view to a regular ESPN headliner.
And it is also set to go behind closed doors at the MGM Grand Arena in Las Vegas.
Lomachenko revealed he took a pay cut to make sure the fight could be agreed, with the Ukrainian now in line to pocket £2.7million.
Unbeaten Lopez had rejected an initial £900,000 offer, but eventually came to terms with Top Rank for an undisclosed increase.