A 34-year-old man has been taken to hospital after a crash in Byford.
A Mitsubishi Lancer and a Holden Commodore collided at the intersection of Hopkinson Road and Orton Road around 9.45pm on Monday.
The force of the crash caused the Lancer to roll onto its roof, trapping the rear passenger.
The passenger received serious injuries and was taken by ambulance to Royal Perth Hospital.
The 23-year-old male driver of the Lancer and the 21-year-old male driver of the Commodore were not injured.
Investigators are urging anyone with dash-cam or mobile phone vision of the Mitsubishi Lancer or Holden Commodore travelling in the area prior to the crash, to upload the vision via this link: https://wapf.au.evidence.com/axon/citizen/public/seriouscrashbyford150321