虚きょを突つく

expression, godan verb (-ku)

catch off guard; take advantage of an opening

Used when someone exploits a moment of inattention, weakness, or unpreparedness. Often appears in competitive, strategic, or interpersonal contexts.

See also: 虚をつかれる

• 相あい手ての虚きょを突ついて、一いっ気きに攻せめ込こんだ。

  We caught the opponent off guard and launched an all-out attack.