Outmanoeuvre (8)
I believe the answer is:
outflank
'outmanoeuvre' is the definition.
(I know that outflank is a is a more specific form of the action of outmanoeuvre)
This is all the clue.
(Other definitions for outflank that I've seen before include "Move round (enemy's) side" , "Move around (an enemy's forces)" , "Pass around the side of" , "Get the better of, especially by surprise action" , "defeat" .)