"It was maybe just driving past."
He said the grey car then came around a corner "driving really fast".
He said when the car's driver noticed the police car, he sped up, and drove into the side of it.
The man then noticed that the car was being pursued by "four or five" other police cars.
Senior Sergeant Stefan McIntyre said police had tried to stop the grey car this morning on Farquhar Rd in Glendene, "due to the driver's behaviour".
"The vehicle fled from police and a pursuit was initiated."
Police said the pursuit lasted about five minutes.
The vehicle was spiked on McLeod Rd, Te Atatu, and stopped shortly after.
"A 30-year-old male passenger, who had an active warrant for his arrest, attempted to flee police but was arrested.
"The 27-year-old driver threatened police with a knife, at which point police have used OC Spray (Oleoresin Capsicum, aka pepper spray) on the man," McIntyre said.
"When this was ineffective, he has been tasered."
Police said no one was injured in the incident and both men are now in custody and assisting police with their enquiries.