First-class
(Other definitions for champion that I've seen before include "Guard" , "Excellent" , "Fight for" , "Stand up for" , "hero" .)
'first-class' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for top-notch that I've seen before include "Grade 1" , "Of the highest quality" , "Excellent (informal)" , "Superb" , "First-rate" .)
'first-class' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for top shelf that I've seen before include "adult" , "Where blue material may be found" .)