The man - believed to be a serial burglar - suffered a knife wound in the altercation with Edwin Dowdy, 83, when he broke into his house in Kenmore, Australia.
News.com.au reports that Dowdy and his wife Jutta, 76, have lived in the property since 1996.
Both Mr and Mrs Dowdy are black belts in the Japanese martial art of Aikido.
Mr Dowdy claims that when he realised there was an intruder in the house, he confronted the burglar with a knife and warned him he was armed.
The man then tried to rush past him and ran on to the blade, before recovering, running on to the balcony and jumping to the ground, leaving a large trail of blood leading out on to the streets below.
Detective Inspector for Brisbane West Robert Hitch said: "Our advice is that people should avoid confronting anybody. It's not my advice that people should arm themselves and confront anyone in a house.
"People have a right to take action to defend their own person, to defend their dwelling and to defend other people. The force that they use must be reasonable and must fit the circumstances, it must be considered in relation to the threat that they're facing."