NT Police have arrested a suspect who they believe inflicted "life-threatening injuries" on a man who then attempted to drive his car through Alice Springs, lost consciousness and crashed into a tree.

According to NT Police, a single-vehicle crash was reported on Larapinta Drive, about 100 metres from the Telegraph Terrace intersection, around 6:30am on Sunday.

"The vehicle had crashed into a tree on the median strip with an adult male driver trapped inside," police said in a statement.

"Investigations indicated the male had suffered injuries inconsistent with a crash and was believed to have been assaulted with an edged weapon prior to entering the vehicle.

"Further investigations confirmed an assault had occurred at a location on Saltwell Street, with the 22-year-old offender known to the victim."

Speaking on ABC Radio Alice Springs this morning, Southern Watch Commander George Ciolka described the driver's injuries as "fairly substantial" and said frontline responders performed life-saving first aid before he was rushed to hospital.

He said the "very young" victim — aged "well under 30" — attempted to drive after the alleged attack but appeared to lose consciousness before colliding with the tree.

"We've cordoned off the scene, he's been removed from the vehicle with the assistance of Northern Territory Fire [and Resuce] Services, he's been then conveyed to Alice Springs Hospital," Commander Ciolka said.

The watch commander said the driver "received immediate medical treatment", which "saved his life", and said the victim remained in a critical condition as of Monday morning.

Police investigations are continuing and charges are yet to be laid, but Commander Ciolka said the matter will "be brought before the courts this morning".

Authorities urge anyone with information to contact 131 444 and quote reference P26297171.