Cause a complete reversal of circumstances (4,3,6)
I believe the answer is:
turn the tables
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cause a complete reversal of circumstances</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for turn the tables that I've seen before include "Bring about a reversal of fortunes" , "Reverse fortune" , "Cause a reversal of fortune" , "effect complete reversal" , "spiritualists used to?" .)