OPP say a 19-year-old is now listed in stable condition after a pickup truck lost control and entered the westbound ditch.
The truck then struck a hydro pole and rolled over.
Elgin County police say the incident took place on Imperial Road around 7:30 a.m. Friday.
Air ambulance transported the Aylmer, Ont. driver to hospital with serious injuries.
Imperial Road was closed between John Wise Line and Conservation Line in order for Hydro One to complete repairs. It has since reopened.