|Real name||John Riel Casimero|
|Nickname(s)||Quadro Alas ("Square Ace")|
|Rated at||Light Flyweight|
|Height||5 ft 4 in (1.63 m)|
February 13, 1990 |
Ormoc, Leyte, Philippines
|Wins by KO||12|
John Riel Casimero (born February 13, 1990 in Ormoc City, Leyte, Philippines), more commonly known as Johnriel Casimero, is a Filipino professional boxer. He is a former IBF Junior Flyweight World Champion and a former WBO Light Flyweight Interim Champion. His moniker is of two languages; quadro is Italian for square and alas is Tagalog for ace.
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.
Light Flyweight Division
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 fought Ramón García Hirales on July 3, 2010, for his first defense of the interim WBO light flyweight title but lost by split decision.
Casimero got his first shot at a world title 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 Division
On February 11, 2012, in Mar del Plata, Buenos Aires, Argentina, Casimero won the IBF interim light flyweight title against Argentinian boxer Luis Lazarte via technical knock out, but after the fight, the audience got angry and threw chairs and a bottle of water, it became the biggest boxing brawl in Argentina. Casimero escaped by going under the boxing ring to protect himself from the angered fans.
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 in the IBF junior flyweight championship.
Philippine Foreign Affairs spokesman Raul Hernandez stated that his country's embassy filed a protest with Argentina's Ministry of Foreign Affairs and is awaiting an explanation. Boxer Alberto Lazarte was banned by IBF for threat, sparking ring riot.
On July 19, 2012, Casimero was declared as the regular IBF Junior Flyweight World 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 Guevarra 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. 
Professional boxing record
|20 Wins (12 knockouts), 2 Losses (1 knockout)|
|Win||20–2||Mauricio Fuentes||KO||1 (12), 2:59||2014–05–03||Waterfront Cebu City Hotel & Casino, Cebu City, Cebu, Philippines||For vacant IBF Light flyweight title.
Casimero lost the title on the scales after failing to make weight, title at stake for Fuentes only.
|Win||19–2||Felipe Salguero||TKO||11 (12) 1:34||2013–10–26||Makati Coliseum, Makati City, Metro Manila, Philippines||Retained IBF Light flyweight title.|
|Win||18–2||Luis Alberto Rios||UD||12||2013–03–16||Megapolis Convention Center, Panama City, Panama||Retained IBF Light flyweight title.|
|Win||17–2||Pedro Guevara||SD||12||2012–08–04||Centro de Convenciones, Mazatlán, Sinaloa||Retained IBF Light flyweight title.|
|Win||16–2||Luis Alberto Lazarte||TKO||10 (12) 1:09||2012–02–10||Club Once Unidos, Mar del Plata, Buenos Aires||Won interim IBF Light flyweight title.|
|Win||15–2||Roemart Sentillas||TKO||2 (10)||2011–10–15||Hoops Dome, Lapu-Lapu, Cebu|
|Loss||14–2||Moruti Mthalane||TKO||5 (12) 1:50||2011–03–26||Nasrec Indoor Arena, Johannesburg, Gauteng||For IBF Flyweight title.|
|Loss||14–1||Ramón García Hirales||SD||12||2010–07–24||Polideportivo Centenario, Los Mochis, Sinaloa||Lost interim WBO Light flyweight title.|
|Win||14–0||César Canchila||TKO||11 (12) 1:40||2009–12–19||Dennis Martínez National Stadium, Managua||Won interim WBO Light flyweight title.|
|Win||13–0||Ardin Diale||KO||8 (12) 1:42||2009–05–28||Cebu Coliseum, Cebu City, Cebu||Retained WBO Asia Pacific Flyweight title.|
|Win||12–0||Allan Ranada||UD||8||2009–05–08||Naga Sports Complex, Naga, Cebu|
|Win||11–0||Liempetch Sor Veerapol||TKO||5 (12) 1:02||2008–10–03||Talisay Sports Complex, Talisay, Cebu||Won vacant WBO Asia Pacific Flyweight title.|
|Win||10–0||Rodel Quilaton||UD||10||2008–08–23||Eusebio Sestoso Memorial Coliseum, Alcoy, Cebu||Won vacant Filipino Flyweight title.|
|Win||9–0||Roemart Sentillas||TKO||3 (10)||2008–07–17||Compostela, Cebu|
|Win||8–0||Roel Honor||TKO||1 (10)||2008–06–12||Baybay, Leyte|
|Win||7–0||Daryl Amoncio||MD||8||2008–04–21||Lapu-Lapu City Auditorium, Lapu-Lapu, Cebu|
|Win||6–0||Jerome Bontog||KO||3 (6)||2008–03–29||Mandaue City Plaza Square, Mandaue, Cebu|
|Win||5–0||Rogen Flores||TD||6 (8)||2008–01–12||Borbon Sports Center, Borbon, Cebu|
|Win||4–0||Dodong Zalde||KO||2 (6) 1:04||2007–12–16||Carmen Sports Center, Carmen, Cebu|
|Win||3–0||Roel Honor||UD||6||2007–08–26||Daanbantayan Sports Center, Daanbantayan, Cebu|
|Win||2–0||Andrew Pal||TKO||2 (4)||2007–08–16||Alcoy Multi-Purpose Sports Complex, Alcoy, Cebu|
|Win||1–0||Lobert Bayo||UD||4||2007–06–03||Barangay Maguikay, Mandaue, Cebu|
- "GETTING TO KNOW JOHN RIEL CASIMERO". philboxing.com. 5 December 2009. Retrieved 2009-12-05.
- "ALCOY RESULTS AND PHOTOS". philboxing.com. 24 August 2008. Retrieved 2008-08-24.
- "MARCIAL, CASIMERO WIN IN TALISAY". philboxing.com. 4 October 2008. Retrieved 2008-10-04.
- "BREAKING NEWS: CASIMERO DOWNS CANCHILA FIVE TIMES EN ROUTE TO 11TH ROUND TKO VICTORY, WINS TITLE". philboxing.com. 20 December 2009. Retrieved 2009-12-20.
- "Casimero gets shot at Calderon’s world crown". FightFan.com. 03-02-2010. Check date values in:
- Ronnie Nathanielsz (March 1, 2011). "CASIMERO BATTLES MTHALANE FOR IBF FLYWEIGHT TITLE". PhilBoxing.com. Retrieved 2011-02-28.
- Edward Chaykovsky (March 26, 2011). "Ndlovu Shocks Molitor To Win, Mthalane KOs Casimero". BoxingScene.com. Retrieved 2011-03-27.
- Philippines protests attack on boxer in Argentina – SI.com – Boxing. Sportsillustrated.cnn.com (2012-02-15). Retrieved on 2012-03-03.
- Boxer Luis Lazarte banned by IBF for threat, sparking ring riot – ESPN. Espn.go.com (2012-02-17). Retrieved on 2012-03-03.
- "IBF DECLARES CASIMERO NEW JUNIOR FLYWEIGHT CHAMPION". philboxing.com. 20 July 2012. Retrieved 2012-07-20.
- Felipe Leon. "Casimero retains IBF jr flyweight belt". Fightnews.com. Retrieved 2012-08-04.
- "John Riel Casimero Professional boxing record". BoxRec.com.
|New title||WBO Light Flyweight Champion
December 19, 2009 – July 24, 2010
Ramón García Hirales
|New title||IBF Junior Flyweight Champion
February 10, 2012 – July 19, 2012
|IBF Junior Flyweight Champion
July 19, 2012 – May 2, 2014
Title next held byJavier Mendoza