Golden Boy Promotions and HBO are finalizing a tripleheader for July 21 at the Hard Rock Hotel & Casino in Las Vegas, the promoter and network told ESPN on Wednesday. It would be headlined by junior middleweight world titlist Jaime Munguia (29-0, 25 KOs), 21, of Mexico, making his first defense against mandatory challenger and former titlist Liam Smith (26-1-1, 14 KOs), 29, of England. Smith was supposed to challenge Sadam Ali for the belt but dropped out because of illness and was replaced by Munguia, who knocked him out in the fourth round on May 12 and inherited the mandatory obligation. The co-feature would be junior lightweight world titlist Alberto Machado (19-0, 16 KOs), 27, of Puerto Rico, making his first defense against mandatory challenger Rafael Mensah (31-0, 23 KOs) of Ghana. The opener would be an all-southpaw middleweight bout between former two-time junior middleweight titlist Demetrius Andrade (25-0, 16 KOs), 30, of Providence, Rhode Island, and Brazil’s Yamaguchi Falcao (15-0, 7 KOs), 30, a 2012 Olympic bronze medalist.