MetService data shows there had been light rain around the time of the crash, which happened on a winding section of SH25 known as Manaia Rd.
Crews were first called at 12.53am, with the first arriving half an hour later.
Fire and Emergency New Zealand sent a rope rescue team from Hamilton along with crews from Coromandel, Manaia Rural, Tapu, Thames and Tairua, northern shift manager Ryan Geen said.
The Level 3 ropes team rescued the person from the vehicle and handed them over to paramedics at 4.47am.
Hato Hone St John sent an ambulance and a helicopter and treated one person in a moderate condition, a spokesman said. They were expected to be flown to either to Auckland or Waikato Hospital.
The crash happened just south of a closed-off section of SH25, which was damaged in the wild weather caused by Cyclone Vaianu over the weekend.
Photos posted by the NZ Transport Agency show subsidence in parts of SH25, which is cut into a steep tree-lined hillside.
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