To fight fire with fire 以牙還牙

use your opponent's technique against them
A phrase which means to use the same method to your opponent as they did to you

21

今日片語

表達 “to fight fire with fire 以火治火” 的含義和漢語成語 “以牙還牙” 及習語 “以其人之道還治其人之身” 相似,都用來表示 “用別人對待你的方式來對待他人” 的意思。需要注意的是,這個表達多指負面的處事方法和手段,在使用時請特別注意。

例句

Our competitors are trying to steal our customers. We are going to have to fight fire with fire and steal some of theirs.
我們的競爭對手試圖挖走我們的顧客。我們得以其人之道還治其人之身,也去他們那裡挖客戶過來。

After her competitors criticised her business approach, she decided to fight fire with fire and go public with her own criticisms of them. 
在競爭對手們批判了她的商業模式之後,她決定以牙還牙,繼而公開談論了她對這些人的看法。

The only way he could beat his opponent was to fight fire with fire and be equally aggressive.
他要想打敗對手,唯一的方法就是以牙還牙,和對方一樣大膽進攻。

BBC 英語教學