Woman sexually assaulted after being asked for a cigarette

Police are appealing for information or witnesses after a woman was sexually assaulted while walking home in Sydney's south-west.

The incident is understood to have occurred in the early hours of yesterday morning when a 48-year-old woman was walking along  Maxwells Avenue, Ashcroft.

Police claim she was near the entrance to Blamfield Oval, when she noticed a cream-coloured, four door ute stop on the opposite side of the road between 2am and 3am.

The pair spoke briefly with the driver asking for a cigarette. 

It's understood the man drove off and the woman continued walking and made her way through the oval, when the man approached her from behind and sexually assaulted her.

The man fled the scene and the woman made her way to hospital a short time later.

Police from Liverpool Police Area Command commenced inquiries into the incident and are asking for any witnesses to come forward.

They have described the man as tall, olive skin, clean shaven, brown eyes, dark hair, and wearing a black and grey striped shirt. He spoke with a New Zealand accent.