Emergency services were called to a domestic violence incident in Hills Road, Mairehau about 9pm on Saturday.
A 23-year-old man was allegedly attempting to flee the scene when he backed down a driveway into the ambulance where the victim was being treated, The Press reported.
As he was pursued by police, he tried to ram the police car several times before being forced off the road, Papanui Sergeant Dean Harker said.
The chase continued on foot before the man produced a baseball bat and threatened to kill the officers, Mr Harker said.
He was subdued with pepper spray and would appear in Christchurch District Court today on 16 charges including assault and threatening to kill.
The ambulance was out of action and it was not yet known if it could be repaired, St John district operations manager Tony Dowell said.
