Floyd Mayweather, Jr. will fight Canelo Alvarez on Sept. 14, the undefeated welterweight champion announced Wednesday night on his Twitter account.
The fight will take place at the MGM Grand in Las Vegas. Golden Boy Promotions said both fighters will fight at the catchweight of 152 pounds. There is no limit on how heavy Alvarez can get post weigh-in.
Alvarez (42-0-1, 30 KOs), 22, is considered the top 154-pounder in the world. He defeated Austin Trout April 20 at the Alamodome in San Antonio to unify the WBC and WBA super welterweight titles.
Mayweather (44-0, 26 KOs) destroyed interim titleholder Robert Guerrero earlier this month winning in a 12-round unanimous decision.
Mayweather, 36, fought Guerrero at 147 pounds and made $32 million for the fight.
The Alvarez fight will be the second of Mayweather's 30-month deal with Showtime/CBS. He signed the deal for up to six fights earlier this year after leaving his longtime television home HBO.