Footballers succeeded in stadium close to capital (7)
I believe the answer is:
arsenal
'footballers' is the definition.
(Arsenal FC is a football team)
'succeeded in stadium close to capital' is the wordplay.
'succeeded' becomes 's' (genealogical abbreviation).
'in' means one lot of letters goes inside another.
'stadium' becomes 'arena' (eg a sports arena).
'close to' says to take the final letters (the close/ending of).
The last letter of 'capital' is 'l'.
's' inserted into 'arena' is 'arsena'.
'arsena'+'l'='ARSENAL'
(Other definitions for arsenal that I've seen before include "array of weapons" , "English football club and military depot" , "A military store of guns and armaments" , "Mil. magazine; FA club" , "Football team - magazine" .)