Just before 5am, police and emergency services were called to Heaslip Road after a Hyundai sedan left the road and crashed into a tree just north of Curtis Road.
The driver, a 70-year-old man from Munno Para West, who was the only person in the car, has been taken to the Royal Adelaide Hospital in a serious condition.
Motorists are advised that Heaslip Road has reopened to all traffic.