Master race's talisman (6)
I believe the answer is:
mascot
'talisman' is the definition.
(synonyms)
'master race's' is the wordplay.
'master' becomes 'm'.
'race' becomes 'Ascot' (Ascot is a racecourse).
'm'+'ascot'='MASCOT'
(Other definitions for mascot that I've seen before include "Thing believed to bring good luck to, say, team" , "Symbolic lucky figure" , "Team's good luck bringer" , "Lucky talisman" , "Good-luck item" .)