World titleholders Gervonta Davis and Nathan Cleverly will defend their belts on the undercard of the Floyd Mayweather-Conor McGregor fight on Aug. 26 at the T-Mobile Arena in Las Vegas, Mayweather Promotions announced Thursday.
Both bouts will be part of the Showtime PPV telecast (9 p.m. ET).
Davis (18-0, 17 KOs), who at 22 is the youngest American world titleholder in boxing, will make the second defense of his 130-pound belt when he takes on Francisco Fonseca (19-0-1, 13 KOs).
Davis, of Baltimore, stormed to a seventh-round knockout of Jose "Sniper" Pedraza on Jan. 14 to win the title. He was even more impressive in a third-round destruction of mandatory challenger Liam Walsh in his first defense, which took place on May 20 in London.
"I'm really excited to fight as the co-main event on the biggest card in combat sports history," Davis said. "I plan to put on a great show for everyone in attendance in Las Vegas and for those who purchase the PPV. I want to thank my team for this incredible opportunity. I'm ready for Floyd Mayweather to pass his torch to me. To my fans, I appreciate all of you. Support me and I'll fight for you."
Fonseca, 23, of Costa Rica, will be boxing in the United States for the first time and taking on his first recognizable opponent. All of his bouts have been in Costa Rica except for two, one in Nicaragua and one in El Salvador.
"I am super grateful for this great opportunity," Fonseca said. "The dream of every young boxer is to fight for the world title and this opportunity comes at the best moment of my career and in the biggest in the history of this sport. I will beat Gervonta Davis and I will shock the world that night."
Two-time world titleholder Cleverly (30-3, 16 KOs), 30, of Wales, will defend his secondary light heavyweight title against Badou Jack (20-1-3, 12 KOs), the former super middleweight world titlist who is moving up in weight.
Jack is promoted by Mayweather Promotions, which worked to get him the opportunity despite the fact that Cleverly had a mandatory defense due against interim titlist Dmitry Bivol. However, the Cleverly and Bivol teams worked out a deal for Bivol (11-0, 9 KOs) to step aside in order for Cleverly to face Jack first. The winner will owe Bivol a fight.
"This is a fight I have wanted ever since Badou Jack moved to light heavyweight and I'm delighted to fight in Vegas on an event like this," Cleverly said. "I've trained long and hard for this fight and I'm ready to be let off the leash. This is the biggest fight of my career so far and I'm going to do a number on Badou Jack on Aug. 26."
Cleverly last fought in October, when he stopped Juergen Braehmer in the sixth round to win the secondary belt on Braehmer's turf in Germany.
Jack, 33, a Sweden native fighting out of Las Vegas, where he trains with Mayweather, is coming off a majority draw in a January super middleweight world title unification fight with James DeGale. Shortly after the action-packed fight, Jack vacated his 168-pound belt and announced he would move up to the 175-pound division.
"I'm thankful for this opportunity and I'm excited about getting another shot at a world title," Jack said. "To be a part of this event and fighting on this card is historic. Nothing beats it. I'm excited to get back in the ring. I'm getting ready to take that belt, and win a title in my second weight class."
Mayweather Promotions CEO Leonard Ellerbe said he was happy to have two of the top Mayweather Promotions boxers in significant fights on the card.
"Gervonta Davis is nothing short of pure boxing talent with dynamite power," Ellerbe said. "Former super middleweight world champion Badou Jack is making his light heavyweight debut, and looking to take the title away from a tough and experienced Nathan Cleverly."
The opening bout of the pay-per-view telecast will feature another Mayweather Promotions fighter, cruiserweight up-and-comer Andrew Tabiti (14-0, 12 KOs), who will take on battle-tested but faded former two-time world titleholder Steve Cunningham (29-8-1, 13 KOs) in a scheduled 10-round fight.
Tabiti, 27, a Chicago native fighting out Las Vegas, will be facing by far his most experienced opponent.
"I've always been dedicated when it comes to training and this camp has been no different," Tabiti said. "I know I am fighting a veteran who has a lot of experience, so I can't slack on my conditioning and training. He's tough and he's only been stopped once and that was when he moved up in weight to heavyweight, so it would be a big statement for me to stop him. This fight is a test for me."
Cunningham, 41, of Philadelphia, is 1-2-1 in his last four bouts. He moved up to heavyweight in 2012 but is now back at cruiserweight, where he was at his best. His only stoppage loss came in 2013 at heavyweight via seventh-round knockout to Tyson Fury, a much bigger man who went on to win the heavyweight world championship.
"This is one of the biggest cards of the decade and its mind-blowing to be a part of it," Cunningham said. "I have to top it off with a victory. Taking on a good, undefeated young prospect is a challenge in itself, but a victory will prove age is just a number. Hard work is a part of my everyday life."