Embassy worker in pain after a race (7)
I believe the answer is:
attache
'embassy worker' is the definition.
(I've seen this in another clue)
'pain after a race' is the wordplay.
'pain' becomes 'ache' (ache is a kind of pain).
'after' is a charade indicator (letters next to each other).
'race' becomes 'tt'.
'a'+'tt'='att'
'ache' after 'att' is 'ATTACHE'.
'in' acts as a link.
(Other definitions for attache that I've seen before include "That ace (anag.)" , "Man with a mission" , "Briefcase or diplomat" , "Small rectangular document case" , "One on embassy staff" .)