Was relieved, having fought without focus (6)
I believe the answer is:
spared
'was relieved' is the definition.
(eg to spare someone pain, to relieve them of it)
'fought without focus' is the wordplay.
'fought' becomes 'sparred' (sparring is a kind of fighting).
'without focus' means to remove the middle letters (focus can mean the centre or essence of something).
'sparred' with its centre removed is 'SPARED'.
'having' acts as a link.
(Other definitions for spared that I've seen before include "Unharmed" , "forgiven" , "Dealt leniently with" , "Treated mercifully" , "did without" .)