A man who tried to scare off intruders by waving a samurai sword was stabbed with his own weapon.
The 65-year-old took the sword from a display in his living room and waved it at three youths who were in the front garden of his flat in east London.
When he looked outside again, the garden was empty but he then found two youths on the landing outside his bedroom.
He shouted at them to leave but an assault followed during which one of the intruders stabbed him with the sword before they ran off taking the weapon with them.
The man suffered multiple stab wounds and was taken to an east London hospital where he remains in a stable condition.
Police are appealing for information about the attack which took place in Barking Road, East Ham, at around 1.30am on Saturday.
A Scotland Yard spokesman said: "The victim awoke to noises outside his bedroom window and saw three youths in his front garden. He shouted at the youths to scare them off.
"He then took a sword that he had on display in his living room and returned to a window and waved it at the youths.
"Moments later he returned to look out of his bedroom window again and saw no-one outside. He walked out of his bedroom to find out that two of the youths were standing on his landing."
He said the sword had not been recovered.
Any witnesses or anyone with any information should call police on 101 or the Violent Crime Unit on 020 7275 5859. To speak anonymously call Crimestoppers call 0800 555 111.