Victory for one girl in vessel (9)
I believe the answer is:
wineglass
'vessel' is the definition.
(I've seen this before)
'victory for one girl' is the wordplay.
'victory' becomes 'win' (a win is a victory).
'for one' becomes 'eg' (both can mean 'for example').
'girl' becomes 'lass' (lass can informally mean a girl).
'win'+'eg'+'lass'='WINEGLASS'
'in' acts as a link.
(Other definitions for wineglass that I've seen before include "Vessel with bowl and stem" , "possibly held in this port? The opposite" .)