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?
Sentence (from "Chris Eubank Jr."): Christopher Livingstone "Chris" Eubank Jr. (born 18 September 1989) is a British professional boxer.
Relevant evidence: No