Reward struggle in slugfest (10)
I believe the answer is:
prizefight
'reward struggle in slugfest' is the definition.
The definition and answer can be both related to natural events as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'reward struggle' is the wordplay.
'reward' becomes 'prize' (I've seen this before).
'struggle' becomes 'fight' (synonyms).
'prize'+'fight'='PRIZEFIGHT'
Can you help me to learn more?
(Other definitions for prizefight that I've seen before include "Public boxing-match for money" , "Professional boxing match" , "Old style boxing match for money" .)