The traumatic, senseless act would have a huge impact on the community as a whole and right across New Zealand, he said.
"I want to reinforce that this was an isolated incident and we are not seeking anyone else."
One local woman spoken to by the Herald was upset by the news a woman had been stabbed to death near her home.
"We weren't home last night but now I'm glad we weren't," she said.
"It's really upsetting. Just the worst thing to happen in your street."
Price also wanted to reassure residents of their presence in the area as they conduct a scene examination and look to speak to witnesses. He also called for anyone who saw anything, or anyone with CCTV footage, to come forward.
"No-one deserves this," Price said.
The knife has been found at the scene.
Emergency services were called to Cheyenne St at 4.20pm yesterday after reports a woman had been stabbed in the street, he said.
Staff arrived soon afterwards and gave assistance to woman who had been critically injured.
The community, and the family, "need to understand the why" given the random nature of the horrific attack, Price said at his media conference.
The Sockburn street is blocked off by a wide police cordon while forensic officers in both blue and white boiler suits scour the scene. Several police tents have been erected in the footpath, spilling into the street.
But they had no effect on the man or his behaviour.
He then went into a private residential driveway and police kept talking to him.
After a further period of negotiation, police fired multiple shots, injuring the man.
Police gave medical assistance to the man before he was rushed to hospital. He is still there in a serious but stable condition. Surgery was completed this morning.
Price urged witnesses to come forward.
"If you have any CCTV footage or cellphone footage, police contact police on 105."
Officers are still getting support, "as this will have a huge impact on them and their whānau".
"This isn't the outcome anyone wanted to happen."
The man's family has been notified and are being supported.
His identity cannot be revealed at this stage. The IPCA has been notified, while a police investigation and a critical incident inquiry is also under way.
Price did not know how many officers fired shots.
It unfolded over 15 to 20 minutes, from when police first came across the man – their vehicle was attacked – before negotiation, tactical options, before the man had "advanced on police and they have used firearms at that stage".
Cordons have been put in place in the area and police ask motorists and pedestrians to follow directions given by emergency services staff.
"Anyone who was in the Cheyenne St area around the time the woman was injured and may have information which could assist police is asked to get in touch via 105 and quote event number P051030807," Superintendent Price said.
Police were also called to an incident in Kaiapoi, north of Christchurch, last night.
They were alerted to a report of a man allegedly threatening a member of the public with a metal bar and a knife on Williams St near Ohoka Rd about 7.20pm.
Price said when police arrived, the man attacked their vehicle with the metal bar. The man made his way to Peraki St where police unsuccessfully tried using a Taser and pepper spray on him.
Police then fired multiple shots, critically injuring him, Price said.