A UK shopkeeper defended himself from an armed-robbery attempt when a man posing as a customer attacked him with a 6″ knife. He ended up defending himself with a vodka-bottle and a chair.
“I picked up a bottle of vodka for him and turned around to put it in the till, I heard a noise behind me and the man had pulled out a knife and was coming at me behind the counter.
“It was a six-inch kitchen knife, my 16-year-old son was right there with me.
“I tried to hit him with the bottle of vodka and tripped over, I kicked him from the ground and then picked up a chair behind the counter and defended myself with it.
“I hit the panic button and the man ran off.
“The police were here within a minute of me hitting the button but it was too late, the guy was already around the corner.”
At a point in the article earlier than my blockquote the shopkeeper says he delivered kicks when he was on the ground. While I am sure he didn’t have formal Krav training, this plus the use of the chair and bottle as improvised weapons make it a classic example of how to fight back. Good for him.