Slight advantage (4)
I believe the answer is:
edge
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">slight advantage</span>' is the definition.<br/ ><span class="explanation-format__explanation">(as in a competitor having the edge)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for edge that I've seen before include "Create borders" , "Bite" , "Some bordering" , "Border or cutting side of knife" , "Sharp side of a blade" .)