John Riel “Quadro Alas” Casimero

John Riel Reponte Casimero (born February 13, 1989) is a Filipino professional boxer and YouTuber, recognized as a three-division world champion. He held the IBF junior-flyweight title (2012–2013), the IBF flyweight title (2016), and the WBO bantamweight title (2019–2022). Known for his explosive style and resilience, Casimero has scored notable victories over César Canchila, Amnat Ruenroeng, Zolani Tete, and Guillermo Rigondeaux. Despite controversies outside the ring, his career achievements across multiple weight classes have established him as one of the Philippines’ most accomplished fighters in the modern era.