Confronts first of famous champions (5)
I believe the answer is:
faces
'confronts' is the definition.
('face' can be a synonym of 'confront')
'first of famous champions' is the wordplay.
'first of famous' becomes 'f' (1st letter of 'famous').
'champions' becomes 'aces' (I've seen this before).
'f'+'aces'='FACES'
(Other definitions for faces that I've seen before include "Confronts" , "Mugs" , "Meets defiantly - moves head accordingly" , "With 1a [NEW], TV talent show" .)