Joshua Pacio is savoring the opportunity to compete alongside Denice Zamboanga at ONE 173, as both world champions seek another big victory on their respective resumes.The 29-year-old reigning ONE strawweight MMA world champion challenges Yuya Wakamatsu for the flyweight crown, while Zamboanga defends her atomweight MMA gold against in-form contender Ayaka Miura.Their five-round scraps will be one of many interesting matchups set for the promotion's star-studded return inside Tokyo's Ariake Arena on Sunday, November 16."I think we're in the peak of our careers right now, me and Denice. And after five years, we don't know what will happen. Maybe we'll see new talents rise," Joshua Pacio told ONE Championship.The Lions Nation MMA representative has a lot on the line as he pursues two-division world championship status inside the Japanese capital city. 'The Passion' was last in action at ONE 171: Qatar, where he wrapped up his rubber match against Jarred Brooks with a sensational second-round TKO inside the Lusail Sports Arena.He reclaimed his strawweight crown just a year prior after Brooks unintentionally spiked him on the head, which resulted in a disqualification.Zamboanga, on the flip side, steps inside the Ariake Arena in Tokyo in search of a first successful title defense.The T-Rex Mixed Martial Arts athlete—the Philippines' first-ever female MMA world champion—earned the division's interim crown after a sublime second-round stoppage win over Alyona Rassohyna at ONE Fight Night 27 this past January. She was elevated to the undisputed ONE atomweight MMA world champion after Stamp decided to relinquish her throne. View this post on Instagram Instagram PostJoshua Pacio on opportunity to become two-division MMA world champ: "Truly grateful"In the same interview with the world's largest martial arts organization, Joshua Pacio tipped his hat to ONE Championship Chairman and CEO Chatri Sityodtong and the organization for providing him the chance to join rarified air in Tokyo."I thank God and I'm truly grateful to Chatri [Sityodtong] & ONE Championship for trusting me with this challenge, and I'm excited to embrace it fully," the ONE world champion continued.This will be the first time Pacio moves up a weight division, though he had previously hinted at a possibility of making a permanent switch to the flyweight division.Fight fans who want to be part of all the action live and in-person at ONE 173 can follow this link.