One of the hitchhikers attacked after being picked up on the West Coast tried to fight off the driver with a small pocket knife, APNZ understands.
Michaela Brandl, 28, was stabbed three times in the carotid artery on the side of her neck, and her Japanese-Dutch companion, Niki Honda, suffered pelvic injuries.
Ms Brandl has told a friend from her hospital bed of how she struggled to open the locked doors of the SUV of her attacker who police believe had already killed Christchurch woman Amy Farrall, 24, the day before.
It's believed that the driver then tried to run over Ms Honda who had escaped from the moving vehicle.
"They're both very lucky. Things could've been a lot worse," a source told APNZ.
"One of the women used a small travel knife, with just a small blade, to try and fight the guy off.
She was pretty desperate."
Sina Saffari spoke to his friend Ms Brandl from her Christchurch Hospital bed where she is recovering and is now in a stable condition.
"[Ms Honda] had to jump out of the car that was moving, and then all of a sudden the driver stopped and turned around,'' said Mr Saffari.
"Michaela thought maybe he was trying to run her [Ms Honda] over.
"She [Ms Brandl] was locked in the car, and she was screaming and asking him to unlock the doors so she could get out."
Mr Saffari said Ms Brandl was traumatised and broke down in tears as she talked - but remarkably, the health-care worker expressed concern and compassion for her attacker.
"We were talking about what someone must be going through to be able to do something like that," said Mr Saffari.
"That person who assaulted her must be in a lot of pain, and I guess she was in a position of feeling compassion for him, that someone was living in such a state where they can actually bring themselves to hurt other people on that level."
The women were hitchhiking down the West Coast when they were picked up in Whataroa by a man driving a blue Nissan Terrano on Sunday.
Aucklander Mr Saffari, 28, met Ms Brandl backpacking in Malaysia in November. She stayed with him when she arrived in New Zealand around three weeks ago.
She spoke to Mr Saffari on the phone from her hospital bed, but her injuries made it difficult for her to speak for long periods, he said.
"She was just traumatised. It sounded like she was in tears. [But] she felt really lucky to be alive."
During the phone call, they didn't dwell much on her injuries or what had happened, Mr Saffari said, because he wanted her to focus on getting better.
"I tried to let her know that there are people who still care for her, and that it may be something that will strengthen her as a human in the future, to have gone through something like that," he said.
"Just the fact she escaped that situation is quite incredible."
He described Ms Brandl as a "beautiful person" who always tried to look at the positive aspect of any situation.
She had been in touch with her sister in Germany, he believed, but was unsure if any members of her family were planning to fly to New Zealand to be with her.
Mr Saffari said he was "quite shocked" by the attack.
"She had gone through Malaysia and Southeast Asia. You'd think that New Zealand would be the last place in the world that you'd expect to encounter something like this.
"For me, it's a real big wake-up call that you never know what's going to happen each day.
"If that can happen in New Zealand to someone who's travelling here, it can happen to anyone, really."
Ms Honda, 27, is said to be recovering well in hospital but needs rest, an official from the Japanese Embassy said in Christchurch yesterday.
The official would not discuss details of the assistance being provided to Ms Honda here, but said the embassy was in touch with her and ready to help with "whatever she needs".
A 38-year-old Otaki man, who has been in police custody since early on Monday morning after he was arrested for allegedly attacking the hitchhikers, has been charged with murdering community support worker Miss Farrall.
In a bedside court appearance, which took place in a Christchurch Hospital ward room yesterday, the man was also charged with the sexual violation of Miss Farrall, aggravated robbery, one charge of wounding with intent to cause grievous bodily harm, and charges of failing to stop and reckless driving.
He was granted interim name suppression.