Fought in ring, asked to absorb pressure (7)
I believe the answer is:
opposed
'fought' is the definition.
('oppose' can be a synonym of 'fight')
'ring asked to absorb pressure' is the wordplay.
'ring' becomes 'O' (O is the shape of a ring).
'asked' becomes 'posed' ('pose' can be a synonym of 'ask').
'to absorb' means one lot of letters goes inside another.
'pressure' becomes 'p' (abbreviation).
'posed' going around 'p' is 'pposed'.
'o'+'pposed'='OPPOSED'
'in' is the link.
(Other definitions for opposed that I've seen before include "Withstood" , "Anti" , "likely to refuse?" , "Confronted" , "Took contrary position to" .)