Question: As of May 2017, Anthony Joshua is ranked as the world's best heavyweight by the Transnational Boxing Rankings Board and BoxRec, the second British boxer, after which British professional boxer, to win both a gold medal at the Olympics and a world title by a major professional sanctioning body, as well as being the first British heavyweight to do so?

Context articles: James DeGale
Shinsuke Yamanaka
Scott Quigg
Chris Eubank Jr.
Terry Flanagan (boxer)
Khalid Yafai
Gilberto Ramírez
Anthony Joshua
Andre Ward
Oleksandr Usyk

James Frederick DeGale, {'1': ", '2': ", '3': ", '4': "} (born 3 February 1986) is a British professional boxer.
 He has held the IBF super-middleweight title since 2015, having previously held the British super-middleweight title from 2010 to 2011, and the European super-middleweight title from 2011 to 2012.
 As of May 2017, he is ranked as the world's best super-middleweight by "The Ring" magazine and the Transnational Boxing Rankings Board, and third by BoxRec.
 As an amateur, DeGale represented Great Britain at the 2008 Olympics, winning a gold medal in the middleweight division.
 By later becoming IBF champion, he became the first British boxer ever to have won both an Olympic gold medal and a professional world title.
Shinsuke Yamanaka (山中 慎介 , Yamanaka Shinsuke , born October 11, 1982) is a Japanese professional boxer, and former WBC and "The Ring" bantamweight world champion, having held the WBC title between 2011 and 2017.
 He made twelve successful defences of the WBC title and his reign is the fourth longest in boxing's bantamweight division.
 As of May 2017, he is ranked as the world's best bantamweight by "The Ring" magazine, BoxRec and the Transnational Boxing Rankings Board.
 He is also ranked as the world's seventh best boxer, pound for pound, by BoxRec, ninth by "The Ring" magazine, and ninth by the Transnational Boxing Rankings Board.
Scott Quigg (born 9 October 1988) is a British professional boxer.
 He held the WBA (Regular) super-bantamweight title from 2013 to 2016, and the British super-bantamweight title from 2011 to 2012.
 As of May 2017, he is ranked as the world's fourth best featherweight by BoxRec, and eighth by the Transnational Boxing Rankings Board.
Christopher Livingstone "Chris" Eubank Jr. (born 18 September 1989) is a British professional boxer.
 He has held the IBO super-middleweight title since February 2017, having previously held the WBA interim and British middleweight titles between 2015 and 2016.
 As of July 2017, Eubank Jr. is ranked as the world's second best super middleweight by BoxRec, sixth by the Transnational Boxing Rankings Board, and seventh by "The Ring" magazine.
 He is the son of former two-weight world boxing champion Chris Eubank.
Terry Flanagan (born 11 June 1989) is a British professional boxer.
 He has held the WBO lightweight title since 2015, becoming the first Englishman to win a world title at lightweight.
 He also held the British lightweight title in 2014, and won the Prizefighter tournament in 2012.
 As of May 2017, he is ranked as the world's third best lightweight by the Transnational Boxing Rankings Board and "The Ring" magazine, and fourth by BoxRec.
Khalid "Kal" Yafai (Arabic: خالد يافعي‎ ‎ ; born 11 June 1989) is a British professional boxer who has held the WBA super-flyweight title since December 2016.
 As an amateur, he represented Great Britain at the 2008 Summer Olympics and won a silver medal at the 2010 European Amateur Boxing Championships as a flyweight.
 As of May 2017, he is ranked as the world's fifth best super-flyweight by BoxRec and the Transnational Boxing Rankings Board, and sixth by "The Ring" magazine.
Gilberto Ramírez Sánchez (born June 19, 1991) is a Mexican professional boxer.
 He has held the WBO super middleweight title since 2016, and is the first boxer from Mexico to win a major world title in that weight class.
 As of September 2017, Ramírez is ranked as the world's best active super middleweight by BoxRec, and second by "The Ring" magazine and the Transnational Boxing Rankings Board.
As of May 2017, Joshua is ranked as the world's best heavyweight by the Transnational Boxing Rankings Board and BoxRec, and second best by "The Ring".
 His knockout-to-win ratio stands at 100%.
 Joshua is the second British boxer, after James DeGale, to win both a gold medal at the Olympics and a world title by a major professional sanctioning body, as well as being the first British heavyweight to do so.
 He is also the second boxer, after Joe Frazier, to win a world heavyweight title whilst still reigning as Olympic champion at the top weight.
Andre Michael Ward (born February 23, 1984) is an American former professional boxer who competed from 2004 to 2017.
 He retired with an undefeated record and held eight world titles in two weight classes, including the unified WBA (Super), WBC, "Ring" magazine, and lineal super middleweight titles between 2009 and 2015; and the unified WBA (Undisputed), IBF, WBO, and "Ring" light heavyweight titles between 2016 and 2017.
 During his reign as light heavyweight champion, Ward was ranked as the world's best active boxer, pound for pound, by "The Ring" magazine and the Transnational Boxing Rankings Board (TBRB), as well as the world's best active boxer in the division by "The Ring", the TBRB, and BoxRec.
Oleksandr Oleksandrovych Usyk (Ukrainian: Олекса́ндр Олекса́ндрович У́сик ) is a Ukrainian professional boxer who has held the WBO junior heavyweight title since 2016.
 As of May 2017 he is ranked as the world's best in the division by "The Ring" magazine, the Transnational Boxing Rankings Board, and BoxRec.
 As an amateur, Usyk won gold medals at the 2011 World Championships and 2012 Olympics, both in the heavyweight division.