Surprise candidate (4,5)
I believe the answer is:
dark horse
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">surprise candidate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for dark horse that I've seen before include "it may be foolish to discount" , "Competitor of unknown capabilities" , "Unknown quantity" , "One about whom little is known" , "Unexpected (possible) winner" .)