Waste material produced by club after fight (5,4)
I believe the answer is:
scrap iron
'waste material' is the definition.
'club after fight' is the wordplay.
'club' becomes 'iron' (iron is a kind of club**).
'after' means one lot of letters go next to another.
'fight' becomes 'scrap' (I've seen this before).
'iron' after 'scrap' is 'SCRAP-IRON'.
'produced by' is the link.
(Other definitions for scrap iron that I've seen before include "Discarded metal" , "for recycling" , "rubbish" , "Waste metal for melting down" .)