Mexico's Francisco Rodriguez Jr. has already been a unified strawweight world champion and now he will go for a junior flyweight title when the 21-year-old heads to the Philippines to challenge hometown titleholder Donnie Nietes in Cebu on July 4, Rodriguez promoter Zanfer Promotions announced on Wednesday.

Donnie Nietes will make his seventh junior flyweight title defense against Francisco Rodriguez Jr. Jay Directo/AFP/Getty Images

"He is a good opponent and should not be overlooked," Nietes said.

Rodriguez (17-2-1, 11 KOs) knocked out Merlito Sabillo in the 10th round in March 2014 to wrest a 105-pound world title in boxing's smallest weight division. In his next fight, last August, Rodriguez won a unanimous decision to unify titles against Japan's Katsunari Takayama in a blazing battle that was selected as the 2014 ESPN.com fight of the year.

Rodriguez then vacated both of his belts, moved up in weight and fought to a draw with Jomar Fajardo in November. But then he easily outpointed him in the Jan. 31 rematch to set up his mandatory shot at Nietes' 108-pound belt.

The 33-year-old Nietes (35-1-4, 21 KOs), who held a strawweight world title until vacating it to move up in weight, won a junior flyweight title in 2011 and will be making his seventh defense when he faces Rodriguez.

Nietes is coming off a one-sided ninth-round knockout of Mexico's Gilberto Parra on March 28.