A bystander threw himself in the path of a motorist who used her car to smash her partner into a footpath before trying to run over him again in Hamilton yesterday.
The woman left her partner badly injured and bleeding, anddrove over a 10m cliff into the Waikato River.
After freeing herself from her car she told a boatie who took her to safety: "I have really, really hurt someone."
Police are praising several people who helped the woman and saved the man from further harm. They are a motorist who saw the incident and followed the woman as she drove off, a kayaker, and a father and son pair in a boat who helped get the woman to safety.
The drama started outside Merv's Superette on Ohaupo Rd about 11.55am when Kanj Patel heard a couple arguing outside his parents' store.
The 15-year-old said he heard the man telling the woman that he was going to leave her "and then she ran him over". "The first time we thought it was just an accident but then the second time we knew it wasn't."
Kanj Patel heard the couple arguing outside his parents' store on Ohaupo Rd. Photo / Christine Cornege
She then tries to drive over the man again, but a middle-aged man runs at the car to try to get her to stop.
The man chases the car as the woman drives off and two pedestrians go to the man's aid.
Kanj Patel, who had recently completed an advanced St John Ambulance first aid course, said the man had severe cuts on his legs, a large bruise on his tailbone and was bleeding from the back of his head.
"I was shocked and I was shaking but I had to do something to help him.
"He was swearing a bit but we took him a cushion and another person got him a towel for his head and we tried to keep him comfortable."
The 44-year-old woman drove about 1km to Cobham Drive, then drove south - trailed by another motorist who saw the incident and had called police.
But she left the road, travelling at least 200m across parkland to the cliff.
Jahmaine Kati was swimming with his younger brother in the river when he heard the car rev shortly before it plunged over the bank.
"It didn't look like she was trying to stop," he said.
Mr Kati said the woman freed herself from the car as it sank.
He said police arrived quickly and officers jumped into the water.
Greg Mitchell and his son Jett Lovegrove-Edlington, 10, took the woman to a boat ramp. Photo / Christine Cornege
Boatie Greg Mitchell told the Herald he was cruising on the river with his son when he saw the woman lying on the riverbank with police officers at her side.
He loaded her and three police officers on board and took them to a boat ramp about a kilometre downstream.
Police last night could not say what charges the woman might face.
