John Riel Casimero

John Riel Reponte Casimero (born February 13, 1989) is a Filipino professional boxer and a fulltime YouTuber.

On August 23, 2008, just a year after turning pro, Casimero defeated Rodel Quilaton for the then vacant Philippines Boxing Federeration (PBF) flyweight title, winning a unanimous decision (UD) through ten rounds.

Following the bout, Casimero moved down one division, to light flyweight, defeating Liempetch Sor Veerapol of Thailand by technical knockout (TKO) in the fifth round to claim the then vacant WBO Asia Pacific Light Flyweight title.

Casimero successfully defended that title two bouts later against Ardin Diale, until he got the biggest break of his career.

On December 19, 2009, in Managua, Nicaragua, Casimero won the then-vacant interim WBO light flyweight title, by defeating former interim WBA Light Flyweight champion César Canchila of Colombia.

Canchila had a record of 28–2 coming into the bout, with his last loss coming from current WBA light flyweight world champion Giovanni Segura, whom he previously defeated for the interim title.

Casimero gave a spectacular performance, the fight being his first outside his home country.

Casimero fought Ramón García Hirales on July 3, 2010, for his first defense of the interim WBO light flyweight title but lost by split decision.

He was able to knockdown Canchila multiple times until the referee finally stopped the bout in the 11th round of the scheduled 12 round interim title fight.

This win can give Casimero a title shot against Iván Calderón of Puerto Rico, who previously defeated Filipino boxer Rodel Mayol.

Casimero got his first shot at a world title when he challenged Moruti Mthalane of South Africa for the IBF flyweight title on March 26, 2011.

He was, however, stopped by the South African in five rounds, therefore marking his second career loss.

He has held world championships in three weight classes; including the IBF junior-flyweight title from 2012 to 2013; the IBF flyweight title in 2016; and the WBO bantamweight title from 2019 to 2022.

Quadro Alas is Tagalog for four of a kind when translated, his moniker means Four Aces.

On February 11, 2012, Casimero, and members of his team were kicked and assaulted when fans in Mar del Plata hurled chairs and stormed the ring following his 10th-round knockout of local Argentine fighter Luis Alberto Lazarte for the IBF interim junior flyweight championship.

After the riot, police escorted Casimero and his team to their hotel and provided protection for them.

Lazarte later visited to apologize.

The Philippines has filed a diplomatic protest to the Argentine government after Argentine fans attacked Casimero in the ring after winning the title bout.

Philippine Foreign Affairs spokesman Raul Hernandez stated that the Philippine Embassy in Buenos Aires filed a protest with Argentina's Ministry of Foreign Affairs and is awaiting an explanation.

Lazarte was banned by IBF for threat, sparking a ring riot.

On July 19, 2012, Casimero was upgraded to the status of full IBF junior flyweight champion because of the inability of Ulises Solis to defend his title on or before October 30.

On his first defense of the IBF junior flyweight title, Casimero faced Pedro Guevara of Mexico on August 4, 2012.

He scored a knockdown in the opening round and fought to a split decision victory.

He successfully made a second defense of his title against WBC Latino light flyweight champion Luis Alberto Rios on March 16, 2013.

His third defense was against Felipe Salguero on October 26, 2013 and he won by eleventh-round knockout.

Following his win against Mauricio Fuentes and Armando Santos, Casimero moved back up to the flyweight division.

On June 27, 2015, he lost his return to flyweight bout via unanimous decision against IBF champion Amnat Ruenroeng in a controversial match.

A rematch on May 25, 2016, Casimero challenged Ruenroeng again for the IBF flyweight title and this time he knocked Ruenreong out with a vicious left hook to the body in the fourth round to become a two-division world champion.

In his second title defence, Casimero faced undefeated Charlie Edwards, on September 10, 2016 on the undercard of Gennady Golovkin vs. Kell Brook at The O2 Arena in London, England.

Casimero was on the offensive for most of the fight, as Edwards was unable to deal with Casimero's ring craft.

Casimero upped the pace in the tenth round, and dropped Edwards with a left hook.

Edwards beat the count, but as soon as he got up, Casimero unleashed a flurry of punches towards the challenger, which prompted the referee to end the fight immediately.

On September 16, 2017, Casimero faced Jonas Sultan for IBF title eliminator.

He lost via 12-round unanimous decision.

Following Casimero's successful title defense against Charlie Edwards in September 2016, he moved up in weight, fighting in non-title bouts at super-flyweight, bantamweight and even one bout against Jose Pech at featherweight before settling at the bantamweight division, where he defeated Ricardo Espinoza Franco via twelfth-round knockout to win the WBO interim bantamweight title in his first fight in the United States on April 20, 2019.

He defended the interim title on August 24, 2019 against Cesar Ramirez, winning via tenth-round knockout, to become full WBO bantamweight titleholder Zolani Tete's mandatory challenger, setting up a showdown with Tete.

On 30 November 2019, Casimero challenged Zolani Tete for his WBO bantamweight title in Birmingham, England.

Despite Tete being the favorite for the fight, Casimero scored a third-round knockout over the long-reigning champion to capture his WBO bantamweight title.

The victory meant that Casimero became a three-division world champion.

Casimero have scheduled to face undefeated unified bantamweight champion Naoya Inoue in a unification clash on April 25, 2020, but the COVID-19 pandemic caused the fight to be cancelled.