隙すきをつく

expression, godan verb (-ku)

exploit a gap; catch off guard

Used when someone takes advantage of a momentary lapse in attention, security, or defense. Often implies a sudden or opportunistic action.

• 相あい手ての隙すきをついて、一いっ気きに攻せめた。

  I exploited an opening in my opponent's defense and attacked all at once.

• 彼かれは忙いそがしいときの隙すきをついて、書しょ類るいにサインをもらった。

  He caught him off guard while he was busy and got him to sign the document.