A man stabbed a dog to death after it attacked two women in Devon.
Mr Davis said the woman's screams will haunt him for a long time
Kayleigh Thorton, 20, from Plymouth suffered severe arm and leg injuries and was taken to Derriford Hospital for surgery. A second woman was also hurt.
Three men had tried to drag the bull mastiff-type dog off the women before Chris Davis, 23, used two of his mother's kitchen knives to kill it.
The incident happened in Manifold Gardens in the Efford area of the city at about 1010 BST.
A hospital spokeswoman has described Ms Thornton's condition as stable.
Ms Thornton is thought to have been looking after the dog at a house in the area.
It is thought she was attacked after trying to intervene when the animal bit a 31-year-old woman who had come to the front door.
Mr Davis said he went to help after hearing one of the women's screams.
"Another man was already using a big stick, but the dog just wouldn't let go and was dragging her up and down the path," he said.
"There was blood everywhere and it was like something from a horror movie."
He added: "The guys were screaming, the girl's screaming so I ran in home, grabbed two kitchen knives from my mum's knife block, and ran up there.
"The girl - she saw I had a knife, and then she started screaming 'Stab it, get it off'.
"I didn't want to hurt the dog, I just wanted to get it off the girl. So I stabbed it in the head and one of the knives snapped so I grabbed the other knife which I had and started stabbing it in the back.
Mr Davis described the dog as "huge and angry" and said it had "gone berserk".
He described how he stabbed the animal about 20 times before it started to stagger and released the woman's arm.
"I've no idea who the woman was, but her screaming will haunt me for a long time," he added.
Mr Davis said the dog collapsed and died while the woman was being taken away to hospital.
Not dangerous breed
The 31-year-old woman also received treatment for injuries sustained in the attack.
Although he was not bitten by the dog, Mr Davis suffered scratches on both arms and will be given a tetanus injection.
He said the whole incident probably lasted no more than about 10 minutes.
The dog's body was taken away by Plymouth City Council.
Sgt Alan Mobbs of Devon and Cornwall Police said the dog was not classed as a dangerous breed. Its owner has now been traced.