This technique is used when your attacker throws an upper-cut punch to your stomach.
When your attacker throws the punch, block the strike with a left-handed downward block.
Grab your attackers wrist with your right hand. Now twist clockwise on the ball of your left foot and place your right foot on the floor so that you are stood to the side of your attacker.
Strike with your left elbow to the side of your attackers head.
Take your left hand round your attackers right arm and grab hold of your gi as high as possible. Now twist their wrist clockwise and push their wrist down to the floor to apply the lock.