Question: Who is most respected for giving the man ranked as the sixth best active boxer one of the toughest fights of his career?
Sentence (from "Guillermo Rigondeaux"): As of May 2017, Rigondeaux is ranked as the world's best super bantamweight by "The Ring", the Transnational Boxing Rankings Board, and BoxRec; "The Ring" also ranks him as the sixth best active boxer, pound for pound.
Relevant evidence: Yes