A 23-year-old Mississauga man has been charged with impaired driving after an early morning crash on Highway 401 in Milton.

A Pontiac Fiero was travelling east near James Snow Parkway at about 4:30 a.m. when the driver lost control and slammed into a Volvo convertible parked on the shoulder, Ontario Provincial Police said.

The impact crushed the front of the Pontiac sports car, trapping a 20-year-old passenger. Sgt. Cam Woolley said it took emergency crews an hour to extricate the Mississauga man.

The passenger was airlifted to Sunnybrook hospital with life-threatening injuries. His condition was later upgraded to stable.

The driver of the Volvo was not near his vehicle at the time of the crash. He was getting help for a flat tire.

The 23-year-old driver of the Fiero, also a Mississauga resident, was arrested at the scene and charged with impaired driving causing bodily harm.

The accident investigation closed all eastbound lanes of the highway between James Snow Parkway and Trafalgar Road for nearly five hours, causing traffic tie-ups.

With a report from CTV Toronto's Jim Junkin