Hunters battle violently to bring about a complete reversal of circumstances (4,3,6)
I believe the answer is:
turn the tables
'bring about a complete reversal of circumstances' is the definition.
(I've seen this before)
'hunters battle violently' is the wordplay.
'violently' indicates an anagram (letters are violently disrupted).
'hunters'+'battle'='huntersbattle'
'huntersbattle' with letters rearranged gives 'TURN THE TABLES'.
'to' is the link.
(Other definitions for turn the tables that I've seen before include "Bring about a complete reversal of circumstances" , "Cause a complete reversal of circumstances" , "Bring about a reversal of fortunes" , "Reverse the positions" , "Gain an advantage from an unfavourable position" .)