Gain an advantage by trickery (4,1,4,3)
I believe the answer is:
pull a fast one
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">gain an advantage by trickery</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for pull a fast one that I've seen before include "Play a sly trick" , "draw with ace sprinter?" , "act unscrupulously" , "Gain an advantage by trickery" , "Cheat" .)