The Sport of Kings (5,6)
I believe the answer is:
horse racing
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">the sport of kings</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 horse racing that I've seen before include "something the Queen loves" , "Sport of kings" .)