Inquiries are underway after a man was critically injured outside a service station at Blacktown overnight, NSW Police say.
Police from Blacktown Local Area Command were called to the business on Sunnyholt Road about 10.20pm today, and found NSW Ambulance paramedics treating a 21-year-old man.
He was taken to Westmead Hospital where he is reported to be in a critical condition.
Police have been told the man had been involved in an incident with a group of friends and was subsequently struck by a car being driven along Sunnyholt Road by a 65-year-old man.
A crime scene has been established and police have spoken with a number of people at the location; the driver has undergone mandatory testing.
Anyone with information about the incident is urged to call Blacktown Police or Crime Stoppers.