Sergeant Brian Leslie of the Henderson police said the man was the sole occupant of the east-bound car as it lost control, hit a bank on the opposite side of the road and "flipped a couple of times" to land on its roof about 50m west of a T-junction with Kay Rd.
A resident who said he was driving home in the opposite direction less than a minute earlier told the Herald how after racing back to the scene he was joined by a woman who had been "freaking out" from being overtaken in her car at speed by the Mitsubishi.
The pair tried to wrestle open the driver's door while another man held his hand from the other side of the car, said the resident, who gave his name only as Kevin.
"The other chap was trying to say keep breathing, an ambulance is coming," Kevin said.
"But he wasn't conscious - he made a couple of groaning signs and we took that as he was sort of hearing us, but I don't think so really."
Kevin said the woman in the other car, who he did not know, indicated she was overtaken about 100m from the crash site before the Mitsubishi cut back in front of her and hit an "undulation".
A 62-year-old man died in a single vehicle crash in Southland on Friday night and a 61-year-old female tourist from Israel was killed when a rental van in which she was a rear-seat passenger rolled down a bank on State Highway 1 near Greta Valley in northern Canterbury on Saturday morning.
She was named by police last night as Liora Keren, who was travelling with her husband and four friends.
Police said she was wearing a seatbelt when the van crossed the centre line and ran through a paddock before rolling down a steep 40m bank.
Another female rear-seat passenger is in a critical condition in Christchurch Hospital's intensive care unit but the van's other four occupants - including the 69-year-old driver - were described as being in comfortable conditions in hospital.
A man thought to be in his late 50s was seriously injured in a collision between a truck and his car on SH4 at Erua, near National Park, about 8pm on Saturday. The truck driver was taken to hospital with a broken leg, said Greenlea Rescue Helicopter pilot Nat Every, of Taupo.
An hour later on SH8 north of Clyde in Central Otago, a 25-year-old Alexandra man suffered serious head injuries after falling from a van travelling at 100km/h, police said.
Witnesses told police he fell while trying to climb out of a window.
A 31-year-old man was yesterday in a critical but stable condition in Auckland City Hospital after his Porsche Cayenne Turbo car went airborne from the Curran St hill leading to the Harbour Bridge just after 2am on Waitangi Day and ended in mud on the shore line.
Waitangi weekend road crashes
• Three killed
• Man in his late 20s or early 30s near Waitakere village, northwest Auckland, yesterday afternoon.
• 61-year-old female Israeli tourist near Greta Vallet, north Canterbury, on Saturday.
• 62-year-old man at Dunearn Southland, on Friday night.
- Additional reporting NZME.