Somebody's O Has Gotta Go

The old adage rings true—somebody's "O" has gotta go. See dates previously undefeated boxers were defeated for the first time in their professional careers and by whom.

Date "O" Went Boxer Defeated By
August 29, 2010 Ivan Calderon Giovanni Segura
August 14, 2010 Chad Dawson Jean Pascal
June 5, 2010 Yuri Foreman Miguel Cotto
November 7, 2009 Harry Joe Yorgey Alfredo Angulo
October 17, 2009 Andre Dirrell Carl Froch
September 26, 2009 Chris Arreola Vitali Klitschko
July 17, 2009 Breidis Prescott Miguel Vazquez
June 20, 2009 Ruslan Chagaev Wladimir Klitschko
June 19, 2009 Adrian Diaconu Jean Pascal
May 30, 2009 Alfredo Angulo Kermit Cintron
April 24, 2009 John Duddy Billy Lyell
March 28, 2009 Ronald Hearns Harry Joe Yorgey
February 27, 2009 Johnathon Banks Tomasz Adamek
December 13, 2008 Demetrius Hopkins Kendall Holt
October 18, 2008 Kelly Pavlik Bernard Hopkins
September 13, 2008 Sergio Mora Vernon Forrest
September 6, 2008 Amir Khan Breidis Prescott
August 29, 2008 Roman Greenberg Cedric Boswell
August 22, 2008 Jason LeHoullier Harry Joe Yorgey
July 26, 2008 Miguel Angel Cotto Antonio Margarito
July 26, 2008 Giovanni Segura Cesar Canchila
June 21, 2008 Giovanni Lorenzo Raul Marquez
June 21, 2008 Dimitri Sartison Mikkel Kessler
June 14, 2008 Mary Jo Sanders Holly Holm
June 5, 2008 James Moore Gabriel Rosado
April 19, 2008 Chris Henry Adrian Diaconu
April 12, 2008 James McGirt Jr Carlos De Leon Jr
March 22, 2008 Michael Katsidis Joel Casamayor
March 21, 2008 Andy Lee Brian Vera
March 8, 2008 Juan Diaz Nate Campbell
February 23, 2008 Sultan Ibragimov Wladimir Klitschko
February 9, 2008 Paul Williams Carlos Quintana
January 26, 2008 Eddie Chambers Alexander Povetkin
December 8, 2007 Ricky Hatton Floyd Mayweather Jr
November 3, 2007 Mikkel Kessler Joe Calzaghe
September 29, 2007 Jermain Taylor Kelly Pavlik
August 11, 2007 Rey Bautista Daniel Ponce de Leon
July 7, 2007 Vic Darchinyan Nonito Donaire
April 14, 2007 Nikolay Valuev Ruslan Chagaev
March 3, 2007 Allan Green Edison Miranda
December 16, 2006 Jason Litzau Jose Andres Hernandez
December 2, 2006 Carlos Quintana Miguel Angel Cotto
November 11, 2006 Calvin Brock Wladimir Klitschko
September 23, 2006 Edison Miranda Arthur Abraham
August 10, 2006 Brian Viloria Omar Nino Romero
June 10, 2006 Paul Malignaggi Miguel Angel Cotto
March 4, 2006 Jeff Lacy Joe Calzaghe
December 2, 2005 Robert Guerrero Gamaliel Diaz
September 24, 2005 Samuel Peter Wladimir Klitschko
August 20, 2005 Rocky Juarez Humberto Soto
August 5, 2005 Sechew Powell Kassim Ouma
May 5, 2005 Cornelius Bundrage Sechew Powell
April 23, 2005 Kermit Cintron Antonio Margarito
February 17, 2005 Daniel Ponce de Leon Celestino Caballero
September 18, 2004 Joey Gilbert Peter Manfredo Jr
August 18, 2004 Peter Manfredo Jr Alfonso Gomez
June 27, 2004 Holly Holm Rita Turrisi
May 8, 2004 Vonda Ward Ann Wolfe
July 12, 2002 Roman Karmazin Javier Castillejo
June 22, 2002 Erik Morales Marco Antonio Barrera
June 1, 2002 Serguei Lyakhovich Maurice Harris
April 13, 2002 Luis Collazo Edwin Cassiani
January 26, 2002 Shane Mosley Vernon Forrest
January 12, 2002 Joel Casamayor Acelino Freitas
November 3, 2001 Zab Judah Kostya Tszyu
September 29, 2001 Felix "Tito" Trinidad Bernard Hopkins
June 15, 2001 Alfonso Gomez Ishe Smith
January 20, 2001 Diego Corrales Floyd Mayweather Jr
December 2, 2000 Fernando Vargas Felix Trinidad
June 24, 2000 Junior Witter Zab Judah
June 23, 2000 Antonio Tarver Eric Harding
September 18, 1999 Oscar De La Hoya Felix Trinidad
February 13, 1999 Ike Quartey Oscar De La Hoya
December 19, 1998 Hasim Rahman David Tua
December 5, 1998 Wladimir Klitschko Ross Puritty
March 21, 1997 Roy Jones Jr Montell Griffin
November 22, 1996 Marco Antonio Barrera Junior Jones
March 15, 1996 Shannon Briggs Darroll Wilson
February 9, 1996 Manny Pacquiao Rustico Torrecampo
November 18, 1994 James Toney Roy Jones Jr
October 17, 1994 Antonio Margarito Victor Lozoya
August 21, 1994 Ronald "Winky" Wright Julio Cesar Vasquez
November 17, 1992 Arturo Gatti King Solomon
November 13, 1992 Evander Holyfield Riddick Bowe

For reigning champions see boxing rankings