It happened on the A377 just before 11pm on Friday night.
A silver Peugeot estate left the road and hit a granite post and some trees.
A 41-year old man was taken to the RD&E with serious head and chest injuries.
He was later transferred to Derriford Hospital in Plymouth.
Officers from the Serious Collisions Investigation Unit are investigating and appealing for witnesses.
Delivery driver sacked after dumping Devon parcels
Massive turnout for 'collapsed road' meeting
Radio Exe listening reaches highest level ever
Seventh weather warning hits Devon
Police probe Airbnb owners after Co-Op heist
