WBC bantamweight champion Nonito Donaire (screengrab)

MANILA – Nonito Donaire and John Riel Casimero will clash in what could be the biggest all-Filipino world boxing title bout.

Both Donaire and Casimero have agreed to unify the World Boxing Council (WBC) and World Boxing Organization (WBO) bantamweight titles in their showdown scheduled for Aug. 14.

Donaire, the reigning WBC champ, first announced the news on Sunday.

"My team does magic. Thank you to Richard Shaefer, Rachel Donaire, PBC (Premier Boxing Champions), TGB [Promotions], and Showtime," Donaire said.

Casimero, the current WBO champ, confirmed the development by simply tweeting two Philippine flag emojis with the letter X in between symbolizing Philippines vs. Philippines.

Donaire's wife Rachel then relayed in her Facebook post how both camps agreed on the all-Filipino battle.

"The invite was from Sean Gibbons of MP Promotions to Nonito: 'Nonito Donaire, you want some of this, it's here for you.' So I just pressed to the invite. Me and Richard talked and worked," the female Donaire shared the initial negotiations.

The 38-year-old Nonito Donaire (41-6 with 27 knockouts) took the WBC title from Nordine Oubaali last month with a huge fourth round knockout win and became the oldest bantamweight champion ever.

On the other hand, Casimero (30-4 with 21 KO's) has been holding the WBO title for two years already. (PNA)