Rival successfully (7)
I believe the answer is:
emulate
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">rival successfully</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for emulate that I've seen before include "Try to match" , "Try to do as well as, follow example" , "Follow suit" , "Strive to equal or surpass" , "Copy - rival" .)