Flinch at victory by church (5)
I believe the answer is:
wince
'flinch' is the definition.
(I know that flinch can be written as wince)
'victory by church' is the wordplay.
'victory' becomes 'win' (a win is a victory).
'by' means one lot of letters go next to another.
'church' becomes 'ce' (abbreviation for Church of England).
'win'+'ce'='WINCE'
'at' is the link.
(Other definitions for wince that I've seen before include "Start back in pain" , "pained" , "Cringe" , "Start painfully" , "Look disgusted" .)