A woman was rushed to hospital with serious injuries as her car ended up on its roof following a two-car crash on the A23.
Police said a Mini One and Citroen C4 Picasso collided on the dual carriageway just over a mile south of the junction with the B2118 in Sayers Common on Saturday afternoon (January 20).
The crash took place at about 4pm and the Mini rolled several times.
A 53-year-old woman, from Hove, was driving the Mini and became trapped in her vehicle. Firefighters from Burgess Hill, Brighton and Haywards Heath along with a heavy rescue tender were called and cut her free using rescue equipment.
She suffered serious spinal injuries and was rushed to the Royal Sussex County Hospital in Brighton.
A 54-year-old woman, also from Hove, who was a passenger in the Mini, suffered minor injuries and was taken to hospital.
The driver of the Citroen, a 31-year-old man, and his 29-year-old female passenger, both from Kent, were also treated in hospital for minor injuries.
The road was closed for several hours while investigations were carried out. It re-opened at 7.45pm.
Police area appealing for anyone with information to contact officers online or call 101 quoting Operation Broadstairs.