Fan to gain immediate victory (6)
I believe the answer is:
winnow
'fan' is the definition.
(I know that fan can be written as winnow)
'gain immediate victory' is the wordplay.
'gain' becomes 'win' (synonyms).
'immediate victory' becomes 'now' (I can't explain this - if you can you should believe this answer much more).
'win'+'now'='WINNOW'
'to' is the link.
(Other definitions for winnow that I've seen before include "Blow air through (grain) to remove chaff" , "Sift out" , "Fan" , "Dehusk grain using air currents" , "Separate chaff from grain" .)