Police at the scene said the 24-year-old woman was the front passenger of the 1999 Mazda Familia her partner, a 27-year-old Kurow man, was driving on Seven Mile Rd.
The front left tyre hit the verge and the car travelled 40m to 50m before rolling and coming to rest upside down on the side of the road.
The woman was taken to Oamaru Hospital then flown by Otago Regional Rescue Helicopter to Dunedin Hospital, where she was in a serious condition last night. The couple’s two children were also in the car.
A 5-year-old girl was taken to Oamaru Hospital by St John as a precautionary measure; a boy aged 1 and the father were not injured.