Fetching details from the dictionary...

to beat; to attack (an enemy); to do away with; to finish off
相手チームを試合で見事に遣っつけた。
We magnificently beat the opposing team.
彼は悪者を一人で遣っつけてしまった。
He defeated the villain all by himself.
敵を素早く遣っつけることができた。
We were able to quickly defeat the enemy.