The offender continued to drive away from the scene and has not been located since.
"The victim's actions and intentions were admirable and show that our community is full of people who will not stand by and watch this type of violent behaviour.
"The good Samaritan suffered head injuries and is now recovering at home. He was lucky to not have received critical injuries.
"We encourage witnesses to this kind of behaviour to call 111 and ask for Police in the first instance, so as not to put their own safety at risk," Detective Sergeant Lee Underhill said.
The incident caused the road to be blocked for a short period and Police would like to talk to anyone who saw the event unfold, Underhill said.
Anyone with information is asked to please contact Lower Hutt CIB on 04 212 3934.