In their struggle to capture victory, few do well (6)
I believe the answer is:
thrive
'do well' is the definition.
(I've seen this before)
'in their struggle to capture victory' is the wordplay.
'in' means one lot of letters goes inside another.
'struggle' is an anagram indicator (I've seen 'struggles' mean this).
'to capture victory' becomes 'v' (I can't explain this - if you can you should believe this answer much more).
'their' is an anagram of 'thrie'.
'thrie' enclosing 'v' is 'THRIVE'.
'few' acts as a link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for thrive that I've seen before include "Grow vigorously, flourish" , "Succeed" , "Prosper, flourish" , "Grow strongly" , "Be successful" .)