Reverse positions (4,3,6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
turn the tables
(Other definitions for turn the tables that I've seen before include "Cause a reversal of fortune" , "Bring about a complete reversal of circumstances" , "effect complete reversal" , "Change from losing to winning" , "Bring about a reversal of fortunes" .)