Saul Alvarez will fight Alfonso Gomez on the Floyd Mayweather Jr.-Victor Ortiz pay-per-view broadcast on Sept. 17, Golden Boy Promotions CEO Richard Schaefer said.
The Alvarez-Gomez fight will take place at Staples Center in Los Angeles, where Alvarez has a large fan base. The Mayweather-Ortiz fight will take place at the MGM Grand in Las Vegas.
"It will be a at the Staples Center and a split site (doubleheader)," Schaefer said. "It's a huge, huge, huge event."
Alvarez (37-0-1, 27 knockouts) stopped Ryan Rhodes in the 12th round on June 18 in his first defense of the WBC junior middleweight title he won by outpointing Matthew Hatton in March.
Gomez (23-4-2, 12 KOs), a former participant in "The Contender" reality series, has won five consecutive fights since he was stopped by Miguel Cotto in 2008 but has fought primarily as a welterweight.