George Groves' bid to claim the WBC super-middleweight title against Badou Jack will be on the Floyd Mayweather undercard in Las Vegas on September 12.
The duo had been scheduled to meet later this month, but now the fight has been finalized at the MGM Grand as Mayweather Jr takes on Andre Berto in what could be his final fight before hanging up his gloves..
Groves, 27, was knocked out by Carl Froch at Wembley last year in an eagerly-awaited rematch, Froch having won their first meeting on a controversial stoppage.
But the Londoner has bounced back from those two defeats, the only losses of his pro career, beating Christopher Rebrasse on points last September and then stopping Denis Douglin two months later.
The Brit is the mandatory challenger for the WBC belt and will now get a third shot at becoming a world champion when he faces the 31-year-old Jack, a Swedish-born fighter who will be making the first defence of the title he claimed when he beat American Anthony Dirrell on a majority decision in April.
"I've been in camp for about two months now. It's been a very good training camp and I'm ready right now to fight. We still have a month to go and we're ready. I've always been strong mentally but I get some extra confidence from having that green belt. You still have to stay humble and keep working hard," Jack said.
"Groves is a pretty good fighter. I definitely think it's going to be an exciting fight. I know he's coming to get what's mine and he's coming to fight. He's fought in the UK in front of a lot of people, but it's a different stage in Vegas.
"I think I'm the overall better fighter. He's going to try to knock me out and I'm going to try to knock him out. It's going to be a great fight. I'm definitely going for the knockout. It's a dream come true to be part of such a big event at MGM Grand for Floyd's last fight, it's a blessing."