As previously reported by Island Echo, a silver Ford Ka lost control on a downhill sweeping left-hand bend and collided with a tree at around 22:23.
Police, Fire and Ambulance crews were all mobilised to the incident, alongside the Dorset and Somerset Air Ambulance.
The incident occurred near Branstone Farm, between Watery Lane and Branstone Cross. The road was closed for several hours but has since re-opened..
The driver of the vehicle, a man in his 20s, sustained serious but not life-threatening head injuries and was taken to St Mary’s Hospital by land.
A passenger in the vehicle, a woman in her 30s, was airlifted to Southampton General Hospital with serious but not life-threatening pelvic and spinal injuries.
The incident is currently under investigation.
Police would like to hear from anyone who was in the area at the time and may have seen anything. Perhaps you saw the vehicle in the moments leading to the collision or you have dash-cam footage?
Anyone with information can make contact with Police by calling 101 quoting 44210064737.