They are due to appear in Auckland District Court tomorrow.
An increased police presence will remain in the area as the scene examination continues.
A post-mortem examination is due to take place this morning.
Police are not looking for anyone else in relation to the matter and any further updates will be issued proactively.
Hato Hone St John said it was called to the incident at 1.31pm and sent two ambulances, one rapid response unit and one manager to the scene.
It said it had also treated two patients in a moderate condition at the scene.
Witness recounts ‘terrifying’ incident
A witness told the Herald a man had been fatally stabbed in front of shocked neighbours.
He said he heard a woman screaming for help and went out onto his townhouse balcony to see what was happening.
To his horror, he said he saw a man stabbing another man in the ground floor yard of a townhouse nearby.
Two women were also in the yard.
Other neighbours could also see the attack from their balconies and homes, the witness said.
After the attack finished, the attacker and the woman waited for police, the witness said.
“Then him and the female ... went and sat down and they waited for police. They didn’t move, they just sat there.”
When the police arrived they detained the man.
As of 3pm, he was still detained at the scene with forensic police taking photos of him, the witness said.
The witness said he had seen the four people having a drink together earlier in the morning about 9-10am and they “looked fine” with each other.
“I’m not sure what happened from then until the incident happened,” the witness said.
The incident was terrifying, the witness said.
“I’ve lived in this neighbourhood for 25 years, in this little cul-de-sac,” he said.
‘We’ve always felt safe, we’ve always been safe here’
However, the incident today also came after a home in the area was shot at last year, the witness said.
“It’s terrifying,” he said.
The witness said he has children, but luckily they did not see the attack.
Another neighbour who spoke to the Herald told of the screaming before emergency services rushed to the scene this afternoon.
“Big police presence bro, with the entire street closed off - not that common to see cops here, but they have been here before.”