Charlie's face smiles having taken lead in race (7)
I believe the answer is:
muggins
'smiles having taken lead in race' is the definition.
I can't tell whether this definition defines the answer.
'charlie's face' is the wordplay.
'charlie' becomes 'mug' (I've seen this before).
'face' becomes 'gins' (I can't explain this - if you can you should give a lot more credence to this answer).
'mug'+'gins'='MUGGINS'
Can you help me to learn more?
(Other definitions for muggins that I've seen before include "A fool (that's me!)" , "Fool (referring to oneself)" , "Poor simpleton, me" , "Fool, sucker" , "idiot" .)