Victoria Police spokeswoman Clair White said the crash between a red Mitsubishi Mirage, a white Mitsubishi Triton and a taxi happened on the corner of Through and Toorak roads about 2.10am on Sunday.

The two people inside the Mirage - a man in his late 20s and the driver, 23-year-old South Yarra woman - were taken to The Alfred hospital, Ambulance Victoria spokesman Ray Rowe said.

"The young lady has upper body injuries and a possible pelvic injury," Mr Rowe said.

The South Yarra woman and her male passenger were trapped in the car for 20 minutes before Metropolitan Fire Brigade firefighters freed them, MFB spokesman Steve Aicher said.

The man suffered shock and minor abrasions, while the 39-year-old Altona Meadows taxi driver was not injured in the crash.

Ms White said the driver of the Mitsubishi Triton, a 35-year-old man from Burwood, tested positive for drink-driving and was helping police with their inquiries.

Police would like to speak to the driver of a Ford Territory taxi who picked up a fare at the corner of Summerhill and Toorak roads, stopping at the crash scene before leaving.

Anyone with information about the smash in asked to phone Crime Stoppers on 1800 333 000, or visit www.crimestoppersvic.com.au.