When I use the grip of my master, my left hand is under your left elbow. And I quickly put my right hand under your knee so that I can throw you on the ground. And there is no counter you can do to me.
This play works best when you are holding your ground but, nonetheless, are being overrun by an aggressively attacking opponent. In the moments before this play, they will be bearing down on top of you, and you are in a decidedly uncomfortable position.
Against what will appear to be a finishing strike, make the cover of the 4th master. Using a sword grip, jam your opponents forearm. In this, you are absorbing the shock of the attack, rather than manipulating the arm. Although your back, as always, should be straight, you will need to drop your weight as much as possible. You can quite feasibly bend your knees so much that the back knee brushes on the ground. Keep your weight on the balls of your toes.
Drop your right hand and slap it under your opponents thigh. This needs to be done very assertively. Contact the inside of your forearm against the back of their thigh, lifting their foot off the ground. Pull your right elbow back to your right hip, springing up with your legs as you do so. This is the moment shown.
Your opponent will twist and fall on their back to your left hand side. Finish them off before they can recover.
This technique, or a variation of it, can be seen in the following plays.