You let him get too close. See, when your assailant gets a hold of your arm like this, you twist under it. Tap it on the forehead like that. It's all that's necessary.
11 seconds sound clip from The Master (1984) - Failure to Communicate (S1E11) sitcom.
You can hear this line at 00:04:47.450 in the Blu-ray version of the TV Series.
Quote context
[...]
- Ninjutsu? How long you been studying?
- This is Max Keller, doing the driving.
- And that's Henry, spinning around on the wheel.
- You're not related to Patrick Keller, the lawyer?
- We'll drop Max off at his father's office, then I'll take you home.
[...]