Senior Sergeant Glenn Saunders of Tauranga police said at the scene that the seriously injured woman had been thrown from the car during the crash.
The 36-year-old was in a critical condition when she was airlifted to Waikato Hospital by the Rotorua-based BayTrust rescue helicopter about 4.30pm.
It was understood a member of the public took some occupants of the car to hospital before emergency services arrived, leading to initial confusion over how many people had been in the car when it crashed.
Ngongotaha fire station officer Lance Taylor said paramedics treated two injured people at the scene.
He said no one was trapped in the vehicle when the fire service arrived. The car had hit the power pole, he said.
Fire crews attended from Tauranga and Rotorua, as well as an operational support crew.
Te Matai Rd was closed for a few hours while emergency services worked at the scene.