Crews from Littleport and Ely were called to a car in a dyke on the A10 at Burnt Fen.
Firefighters using specialist cutting equipment extricated a female casualty, with chest and leg injuries, from the car.
Crews also attended from Downham Market and Kings Lynn in Norfolk.
An air ambulance crew and Hart Team were in attendance.
Cambridgeshire crews returned to their station by 12.04pm.