The MailOnline reports that mother-of-two Helen Coulston, 46, is now fighting for life at St Vincent’s hospital after being knifed when she answered the front door of her Dover Heights home in Sydney’s east.

Peter, a builder working nearby, heard her desperate screams for help and came running to her aid as the blood-soaked woman managed to wrestle the blade away from the knifeman before throwing it into the street.

The Trident Design and Construction worker picked up the knife as the attacker closed in and demanded he hand it over.

He refused and the tense standoff eventually ended when the attacker jumped into a white Audi and sped off.

But the quick-thinking tradie called the police and gave them the registration details.

The luxury car was then intercepted by heavily-armed police on Campbell Parade at Bondi Beach moments later and a man, 46, was arrested. He is now facing a charge of attempted murder.

Peter and his construction team stayed with the woman and rendered aid until a NSW Ambulance crew arrived at the bloody scene.

Johnny Spili, Peter's boss, told Daily Mail Australia he couldn't be more proud of his worker, who was working on a house two doors down at the time of the attack.

“I am very proud of Peter's conduct and how he intervened. I am very happy he contained himself, stood his ground protected the lady and then he kept his cool, it could have turned out so much worse,” said Spili. 

Spili said Peter had called him multiple times this afternoon since the attack and said he was shook up but he is 'a tough kid'

He said Peter told him the woman managed to grab the knife off the attacker and throw it away for Peter to then pick it up.