The crash was reported at about 9:50 p.m. on southbound Highway 101 just north of Ignacio Boulevard, CHP Sgt. M. Bartholomew said.
Witnesses said a 2002 Chrysler convertible was driving erratically on the highway when the car struck a small dirt embankment on the right shoulder, overturned and landed on its right side in the No. 3 and 4 lanes, according to Bartholomew.
The male passenger, who appeared to have injured his arm, was seen leaving the car and running from the area, Bartholomew said.
The driver, 32-year-old Beser Bedir, of Novato, was trapped and suffered major injuries, according to Bartholomew. He was extricated from the wreck and taken to Marin General Hospital.
Bedir was arrested for suspicion of driving under the influence of alcohol, Bartholomew said.
The passenger of the car has not been located. Anyone with information about the crash is asked to call the California Highway Patrol in Corte Madera at (415) 924-1100.