A specific person finished first, we hear (3)
I believe the answer is:
one
'a specific person' is the definition.
(an individual)
'finished first we hear' is the wordplay.
'finished first' becomes 'won' (I've seen this in another clue).
'we hear' indicates a 'sounds like' (homophone) clue.
'won' sounds like 'ONE'.
(Other definitions for one that I've seen before include "United" , "Hour after midnight" , "Single, sole" , "Ace" , "Figure" .)