Photo: Georgia Matts

The 27-year-old woman was walking north-bound in the south-bound lanes of the Greensborough Highway, between Grimshaw and Elder streets, when she was struck by a vehicle about 4.30am on Sunday.

The vehicle has failed to stop and fled the scene.

While lying injured on the road, she was nearly struck by a second vehicle whose occupants stopped and called for help.

The Frankston North woman was taken to hospital with serious injuries that required surgery.

Greensborough Highway Patrol members are investigating the incident.

Any witnesses or anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au.