Former world title challenger Joseph 'JoJo' Diaz Jr. (29-1, 15 KOs) will return to the ring against Jesus Cuadro (18-5, 14 KOs) in the main event of the Sept. 21 edition of Golden Boy Fight Night on Facebook Watch at The Auditorio del Estado in Mexicali, Mexico. The fights will be streamed live globally on Facebook Watch via the Golden Boy Fight Night Page.

Diaz Jr. is a 26-year-old southpaw who represented the U.S. at the 2012 Olympic games in London. Immediately after, Diaz Jr. signed with Golden Boy and began a stellar career that has included fights against Gary Russell Jr., Jesus Rojas, and Rafael "Big Bang" Rivera. Now at 130 pounds, the native of South El Monte, Calif. is in search of another world title opportunity, but first he'll return against a tough opponent in his second headlining event on Facebook Watch.

"I'm ready to defend my WBA Gold Title in Mexicali," said Joseph Diaz Jr. "I want to show everyone that I am proud to be Mexican American. I'm ready to put on an entertaining performance for my raza. I'm going to put everything on the line for those who have been with me since the beginning."

Nicknamed "The Shotgun," Cuadro is a 33-year-old puncher who has traveled to places like Mexico, the Dominican Republic, Argentina and Russia in search of big challenges. This nomadic native of Caracas, Venezuela will now look to pull off an upset of a lifetime against Diaz Jr. in the Mexican state of Baja California.

"Joseph Diaz Jr. is an elite fighter, so we have to defeat him," said Jesus Cuadro. "I'm a natural 130-pounder, and I've even fought at lightweight. That will give me an advantage because I'm going to go into the fight with a lot of strength. I can't tell you how the fight will finish, but I can tell you that I'll be walking away with my hand raised in victory."

In the co-main event, Leonardo "Leon" Baez (16-2, 9 KOs) of Mexicali, Mexico will defend his NABA Super Bantamweight Title for the first time against Edison "El Cabezon" Perez (19-4, 14 KOs) of Ciudad Bolivar, Venezuela in a 10-round fight. Baez is returning after his dominant victory against two-time Olympian Alberto "Impacto" Melian.

Cristian Bielma (13-3, 5 KOs) of Mexicali, Mexico will participate in a 10-round lightweight fight against a soon-to-be-announced opponent.

Jan "Nito" Salvatierra (2-0, 1 KO) of Los Cabos, Mexico will battle Juan Borja (0-1) of La Paz, Mexico in a four-round flyweight bout.

Angel Villa (6-0, 4 KOs) of Mexicali, Mexico will return against Dilan Loza (15-2, 9 KOs) of Mexicali, Mexico in an eight-round welterweight battle.

Genaro Rodriguez (5-5-1, 1 KO) of Guadalupe Victoria, Mexico will fight Gustavo Guerrero (10-2, 3 KOs) of Mexicali, Mexico in a six-round super bantamweight fight.

Roberto Perez (4-0, 4 KOs) of Mexicali, Mexico to fight Victor Perez (1-2) of Mexicali, Mexico in a super bantamweight bout scheduled for six rounds.

Arturo Torres (4-0, 2 KOs) of Mexicali, Mexico will return against Esteban Vargas (1-1, 1 KO) of Mexicali, Mexico in a four-round super flyweight fight.

Jose Adame (2-0, 1 KO) of Mexicali, Mexico will face Jorge Rios (2-11, 1 KO) of Mexicali, Mexico in a four-round middleweight battle.

Melissa Meras (5-0, 1 KO) of Mexicali, Mexico will return against Jazmin Medina (1-0, 1 KO) of Calexico, Mexico in a four-round super flyweight bout.