Mathew Hall stabbed near heart in terrifying assault at Helensburgh home.

Those were the terrifying words Deborah Hall heard her beloved son say as he lay collapsed on the front steps of the porch of her Helensburgh home.

Ms Hall thought she didn't hear him correctly so Mathew repeated, "I've been stabbed".

The 40-year-old had struggled to make it to the steps, his white shirt had turned red, soaked in blood.

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Ms Hall immediately called an ambulance for her son, who had been stabbed close to his heart only moments before at about 2.30am Monday night.

Mr Hall said her son went outside after he heard his red Alfa Romeo's windows being smashed.

Glass debris was strewn across the driveway on Monday morning.

Ms Hall told the Mercury she kept her son talking to her, as he dropped in and out of consciousness, until paramedics arrived.

"For him to be stabbed so close to the heart, that is hurting me," Ms Hall said.

"It has been really hard. Mat doesn't deserve to be stabbed.

"I hope God doesn't take him. I just want God to leave him with me.

"I've lost one son 11 years ago and I can't lose another one.

"I pray to God Mat is OK."

Ms Hall had been crying throughout the night and into the morning as she anxiously waited to hear from the St George Hospital to update her on Mat's emergency surgery.

"He has got to come home to his Mum," she said.

"I am dying. I have emphysema.

"He is my carer and he looks after me."

Emergency services were called to the home on Merrigong Place following reports of a stabbing about 2.30am, a police spokeswoman said.

Wollongong officers arrived a short time later and found Mr Hall with a stab wound to his chest and a 21-year-old man with facial injuries.

Both men were treated by NSW Ambulance paramedics before being taken to hospital.

Mr Hall underwent surgery and remains in hospital in a stable condition on Monday afternoon. He remains in intensive care on a ventilator.

The 21-year-old man was arrested and remains in hospital under police guard.

A crime scene was established at the home and an investigation commenced into the circumstances surrounding the incident.

Crime scene officers continued to collect evidence at the scene until 11am Monday.

Meanwhile, a 25-year-old man presented to Wollongong Hospital with a stab wound to his right side about 3.30am.

His injuries are not considered life-threatening.

Police believe all three men are known to each other and officers are continuing to investigate the incident.

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