The incident occurred at Glendora Ridge Road and Mt. Baldy Road around 12:35 a.m.
According to California Highway Patrol, the car went off the road and down about 500 feet, sparking a small brush fire.
The injured female passenger crawled from the wreckage and managed to hike back up the hill to get help. She was hoisted into a helicopter and flown to a local hospital with a broken arm and lacerated thigh.
The driver was killed. Rescue crews could not get to him until the fire, which burned less than an acre, was brought under control.
The cause of the car accident remains under investigation.