Trouble The Water To Catch The Fish (混水摸魚 ) from the Thirty-Six Stratagems (三十六計)

混水摸魚

乘其陰亂，利其弱而無主。隨，以向晦入宴息。

"Before engaging your enemy's forces create confusion to weaken his perception and judgment. Do something unusual, strange, and unexpected as this will arouse the enemy's suspicion and disrupt his thinking. A distracted enemy is thus more vulnerable."

Quoted from Chinese Classics and Translations