John Riel Casimero
John Riel Reponte Casimero is a Filipino professional boxer and YouTuber. He has held world championships in three weight classes including the International Boxing Federation junior-flyweight title from 2012 to 2013, the IBF flyweight title in 2016, and the World Boxing Organization bantamweight title from 2019 to 2022. Quadro Alas is Tagalog for four of a kind when translated, his moniker means Four Aces. He has faced significant controversy in his boxing career and his frequent mischief and misconducts, have turned him into one of the most talked-about boxer in the Philippine social media scene.
Professional career
Early career at flyweight and light-flyweight
On August 23, 2008, just a year after turning pro, Casimero defeated Rodel Quilaton for the then vacant Philippines Boxing Federeration flyweight title, winning a unanimous decision through ten rounds. Following the bout, Casimero moved down one division, to light flyweight, defeating Liempetch Sor Veerapol of Thailand by technical knockout 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.Light-flyweight
Casimero vs. Canchila
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. 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 vs. Hirales
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.Flyweight
Casimero vs. Mthalane
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.Return to light-flyweight
Casimero vs. Lazarte
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.
Casimero vs. Guevara
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.
Return to flyweight
Casimero vs. Ruenroeng I & II
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.Casimero vs. Edwards
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.Super flyweight
On September 16, 2017, Casimero faced Jonas Sultan for IBF title eliminator. He lost via 12-round unanimous decision.Bantamweight
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.Casimero vs. Tete
On November 30, 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.Cancelled bout vs. Naoya Inoue
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. He instead faced the undefeated Duke Micah, ranked #11 by the WBO, in his first WBO bantamweight title defense on September 26, 2020, on the undercard of The Charlos vs. Dereyvanchenko and Rosario. Casimero recorded another stoppage win, again in the third round, to retain his WBO belt.Casimero vs. Rigondeaux
It was announced on June 19, 2021, that WBC champion Nonito Donaire would replace Rigondeaux, but when the fight between Casimero and Donaire fell apart over insults directed at Donaire's wife, Rigondeaux stepped back in to fight Casimero as had been originally planned. Casimero faced two-time Olympic gold medalist Guillermo Rigondeaux on August 14, 2021. In a low-key affair that saw the CompuBox record broken for fewest combined landed punches in a 12-round fight, Casimero pressured his opponent all night, fighting on the front foot and throwing more punches than Rigondeaux, who was reluctant to engage. Casimero was rewarded with a split decision victory, with scores of 117–111 and 116–112 in his favor, and 115–113 in favor of Rigondeaux.In his post-fight interview, Casimero criticized his opponent's extremely passive gameplan, saying "I'm focused on knockout, but Rigondeaux always runs. Rigondeaux just always runs. No fighting." He continued by reaffirming that it is his intention to unify the bantamweight division, targeting the division's other titleholders, Nonito Donaire and Naoya Inoue. Casimero concluded his interview by issuing the middle finger to Inoue.
Cancelled bout vs. Paul Butler
Casimero had been scheduled to fight his mandatory challenger and former IBF bantamweight champion Paul Butler on December 11, 2021, at Coca-Cola Arena in Dubai, United Arab Emirates. Casimero withdrew before the weigh-ins after being rushed to the hospital due to viral gastritis. The bout had been rescheduled on April 22, 2022, at M&S Bank Arena in Liverpool, England but Casimero was not permitted to fight by the British Boxing Board of Control due to medical guidelines violation by using a sauna to cut weight "in close proximity" to the fight. Casimero's late replacement, fellow Filipino Jonas Sultan, lost to Butler by unanimous decision, making Butler the interim champion. On May 4, the WBO stripped Casimero of the title, with Butler supplanting him.Super Bantamweight
On December 3, 2022, Casimero fought Japan's Ryo Akaho in a match in South Korea that was initially ruled a no contest before being revised to a knockout in favor of Casimero by the Korean Boxing Member Commission, which reviewed the matter upon the Games and Amusements Board's appeal. Later on, Casimero officially signed a contract under Treasure Boxing Promotion with the Japanese startup led by former world champion and CEO Masayuki Ito in February 2023. Casimero made a successful homecoming, dethroning Namibia's Fillipus Nghitumbwa via unanimous decision win to claim the WBO Global super bantamweight title at the Okada Manila in Paranaque City on May 13, 2023.Casimero vs. Oguni
Casimero made his debut in Japan by taking on former IBF super bantamweight champion Yukinori Oguni on October 12, 2023, at the Ariake Arena in Tokyo, Japan. The bout ended with a Controversial Technical Draw because of an accidental headbutt.On October 13, 2024, Casimero won the super bantamweight match after defeating Saul Sanchez via knockout on the first round in Yokohama. On October 15, he was suspended by the Japan Boxing Commission for one year after he had exceeded the 122-pound weight-in limit prior to the match on October 12.
Super Featherweight
Casimero vs. Kameda
In 2025, Casimero has signed with Kōki Kameda's SaikouXLush Boxing Promotion for three fights. Casimero previously inked a deal with Masayuki Ito’s Treasure Boxing Promotion in 2023, but their partnership didn’t pan out after just four fights. It was announced during the press conference on September 19, 2025 in Japan that Casimero is scheduled to fight Kyonosuke Kameda in a 10-round match moving up to Super featherweight division at a catchweight of at Bishkek Arena in Kyrgyzstan on October 25, 2025. Casimero lost via Unanimous Decision.Casimero vs. Mizokoshi
Casimero defeated Mizokoshi Tomu by technical knockout in the fifth of their scheduled eight-round contest at Aichi Sky Expo in Tokoname, Japan, on 27 December 2025.Professional boxing record
| No. | Result | Record | Opponent | Type | Round, time | Date | Location | Notes |
| 41 | Win | Mizokoshi Tomu | TKO | 5, 1:10 | Dec 27, 2025 | Aichi Sky Expo, Tokoname, Japan | ||
| 40 | Loss | 34–5–1 | Kyonosuke Kameda | UD | 10 | Oct 25, 2025 | Bishkek Arena, Bishkek, Kyrgyzstan | |
| 39 | Win | 34–4–1 | Saul Sanchez | TKO | 1, 2:41 | Oct 13, 2024 | Yokohama Budokan, Yokohama, Japan | Casimero missed weight |
| 38 | Draw | 33–4–1 | Yukinori Oguni | TD | 4, 0:27 | Oct 12, 2023 | Ariake Arena, Tokyo, Japan | Split TD: Oguni cut from an accidental head clash |
| 37 | Win | 33–4 | Fillipus Nghitumbwa | UD | 12 | May 13, 2023 | Okada Manila Hotel and Casino, Parañaque, Philippines | Won WBO Global super bantamweight title |
| 36 | Win | 32–4 | Ryo Akaho | KO | 2, 2:25 | Dec 3, 2022 | Paradise City Plaza, Incheon, South Korea | Originally a No Contest. It was changed to a KO after a review by the Korea Boxing Member Commission. |
| 35 | Win | 31–4 | Guillermo Rigondeaux | SD | 12 | Aug 14, 2021 | Dignity Health Sports Park, Carson, California, US | Retained WBO bantamweight title |
| 34 | Win | 30–4 | Duke Micah | TKO | 3, 0:54 | Sep 26, 2020 | Mohegan Sun Arena, Montville, Connecticut, US | Retained WBO bantamweight title |
| 33 | Win | 29–4 | Zolani Tete | TKO | 3, 2:14 | Nov 30, 2019 | Arena Birmingham, Birmingham, England | Won WBO bantamweight title |
| 32 | Win | 28–4 | Cesar Ramirez | KO | 10, 2:23 | Aug 24, 2019 | San Andres Civic & Sports Center, Manila, Philippines | Retained WBO interim bantamweight title |
| 31 | Win | 27–4 | Ricardo Espinoza Franco | KO | 12, 0:44 | Apr 20, 2019 | Dignity Health Sports Park, Carson, California, US | Won WBO interim bantamweight title |
| 30 | Win | 26–4 | Kenya Yamashita | TKO | 6, 0:47 | Feb 16, 2019 | Midas Hotel and Casino, Pasay, Philippines | |
| 29 | Win | 25–4 | Jose Pech | TKO | 2, 1:41 | Jul 21, 2018 | Casino Hipodromo Agua Caliente, Tijuana, Mexico | |
| 28 | Loss | 24–4 | Jonas Sultan | UD | 12 | Sep 16, 2017 | Waterfront Hotel & Casino, Cebu City, Philippines | |
| 27 | Win | 24–3 | Jecker Buhawe | UD | 6 | Jun 25, 2017 | Iligan City, Philippines | |
| 26 | Win | 23–3 | Charlie Edwards | TKO | 10, 1:57 | Sep 10, 2016 | The O2 Arena, London, England | Retained IBF flyweight title |
| 25 | Win | 22–3 | Amnat Ruenroeng | KO | 4, 2:10 | May 25, 2016 | Diamond Court, Beijing, China | Won IBF flyweight title |
| 24 | Loss | 21–3 | Amnat Ruenroeng | UD | 12 | Jun 27, 2015 | Indoor Stadium Huamark, Bangkok, Thailand | For IBF flyweight title |
| 23 | Win | 21–2 | Armando Santos | TKO | 2 | Dec 13, 2014 | Salón Las Palmas, Pesquería, Mexico | |
| 22 | Win | 20–2 | Mauricio Fuentes | KO | 1, 2:59 | May 3, 2014 | Waterfront [Cebu City Hotel & Casino|Waterfront Hotel & Casino], Cebu City, Philippines | |
| 21 | Win | 19–2 | Felipe Salguero | TKO | 11, 1:34 | Oct 26, 2013 | Makati Coliseum, Makati, Philippines | Retained IBF junior-flyweight title |
| 20 | Win | 18–2 | Luis Alberto Rios | UD | 12 | Mar 16, 2013 | Megapolis Convention Center, Panama City, Panama | Retained IBF junior-flyweight title |
| 19 | Win | 17–2 | Pedro Guevara | SD | 12 | Aug 4, 2012 | Centro de Convenciones, Mazatlán, Mexico | Retained IBF junior-flyweight title |
| 18 | Win | 16–2 | Luis Alberto Lazarte | TKO | 10, 1:09 | Feb 10, 2012 | Club Once Unidos, Mar del Plata, Argentina | Won IBF interim junior-flyweight title |
| 17 | Win | 15–2 | Roemart Sentillas | TKO | 2 | Oct 15, 2011 | Hoops Dome, Lapu-Lapu, Philippines | |
| 16 | Loss | 14–2 | Moruti Mthalane | TKO | 5, 1:50 | Mar 26, 2011 | Nasrec Indoor Arena, Johannesburg, South Africa | For IBF flyweight title |
| 15 | Loss | 14–1 | Ramón García Hirales | 12 | Jul 24, 2010 | Polideportivo Centenario, Los Mochis, Mexico | Lost WBO interim light flyweight title | |
| 14 | Win | 14–0 | César Canchila | TKO | 11, 1:40 | Dec 19, 2009 | Dennis Martínez National Stadium, Managua, Nicaragua | Won WBO interim light flyweight title |
| 13 | Win | 13–0 | Ardin Diale | KO | 8, 1:42 | May 28, 2009 | Cebu Coliseum, Cebu City, Philippines | Retained WBO Asia Pacific light flyweight title |
| 12 | Win | 12–0 | Allan Ranada | UD | 8 | May 8, 2009 | Sports Complex, Naga, Philippines | |
| 11 | Win | 11–0 | Phaiboon Chumthong | TKO | 5, 1:02 | Oct 3, 2008 | Sports Complex, Talisay, Philippines | Won vacant WBO Asia Pacific light flyweight title |
| 10 | Win | 10–0 | Rodel Quilaton | UD | 10 | Aug 23, 2008 | Eusebio Sestoso Memorial Coliseum, Alcoy, Philippines | Won vacant |
| 9 | Win | 9–0 | Roemart Sentillas | TKO | 3 | Jul 17, 2008 | Compostela, Philippines | |
| 8 | Win | 8–0 | Roel Honor | TKO | 1 | Jun 12, 2008 | Baybay, Philippines | |
| 7 | Win | 7–0 | Daryl Amoncio | 8 | Apr 21, 2008 | City Auditorium, Lapu-Lapu, Philippines | ||
| 6 | Win | 6–0 | Jerome Bontog | KO | 3 | Mar 29, 2008 | City Plaza Square, Mandaue, Philippines | |
| 5 | Win | 5–0 | Rogen Flores | 6 | Jan 12, 2008 | Sports Center, Borbon, Philippines | ||
| 4 | Win | 4–0 | Dodong Zalde | 2, 1:04 | Dec 16, 2007 | Sports Center, Carmen, Philippines | ||
| 3 | Win | 3–0 | Roel Honor | UD | 6 | Aug 26, 2007 | Sports Center, Daanbantayan, Philippines | |
| 2 | Win | 2–0 | Andrew Pal | 2 | Aug 16, 2007 | Multi-Purpose Sports Complex, Alcoy, Philippines | ||
| 1 | Win | 1–0 | Lobert Bayo | 4 | Jun 3, 2007 | Barangay Maguikay, Mandaue, Philippines |
Exhibition boxing record
| No. | Result | Record | Opponent | Type | Round, time | Date | Location | Notes |
| 1 | Win | 1–0 | Billy Jack Sanchez | TKO | 3, 1:40 | May 9, 2021 | Glenford Fitness Boxing Gym, Taguig, Philippines |
Titles in boxing
Major world titles:Interim world titles:
- WBO interim light flyweight champion
- IBF interim light flyweight champion
- WBO interim bantamweight champion
- flyweight champion
- WBO Asia Pacific light flyweight champion
- WBO Global super bantamweight champion
Awards and recognition
- 2024 1st Pacquiao-Elorde Awards Night
- 2023 Gabriel "Flash" Elorde Memorial Boxing Awards "Boxer of the Year"
- 2010 28th SAC-SMB Sportswriters Association of Cebu Sports Awards
Controversy
Acts of lasciviousness
In 2022, Casimero was charged with acts of lasciviousness and sexual assault over the alleged molestation of a 17-year-old whom he had invited to his hotel room in Taguig in June 2021. Casimero's brother and trainer, Jayson, called the charges “fabricated”.Threats against boxing personalities
On September 2024, DWAR Abante Radyo reported the dispute about John Riel and his brother Jayson during a Facebook live stream in Jayson's account Quadro Alas it’s my boy. Respondent exclaimed the following expletives and threatening remarks directed at sports commentator and social media personality, Pow Salud. Due to constant public arguments, heated atmosphere, and controversies surrounding the Casimero brothers. Salud has now officially stopped making articles, video contents, and coverage about Casimero.On October 2024, following Casimero's victory against Saul Sanchez, international boxing judge Edward Ligas reported that Casimero and his entourage confronted him at Narita Airport in Japan, with Ligas alleging threatening behavior from Casimero's group over negative commentary he had made about the boxer, and accused Ligas of "spreading lies" and "attacking them". Ligas has indicated he is considering formal legal action against John Riel Casimero and his brother and trainer, Jayson, at the Games and Amusements Board and the Japan Boxing Commission. Ligas expressed apprehension that a future encounter might escalate to physical confrontation.