A great white shark attacked on a teenage surfer at a Sydney beach early Sunday morning.

Andrew Lindop, 15, is lucky to be alive after he was bitten on the leg while surfing with his father at North Avalon.

His ordeal was the third shark attack in Sydney in as many weeks. All beaches from Newport to Palm Beach were closed and swimmers were ordered from the water at Maroubra after a shark was spotted circling offshore.

Charles Lindop heard his son scream he had been bitten and helped him paddle to shore where two young surfers helped stem the bleeding from his left thigh.

After undergoing surgery at Royal North Shore Hospital the teenager, a student at St Augustine's College in Brookvale, was able to move his toes and it is hoped his leg will be saved.

Surfwatch Australia shark spotter Michael Brown said it was likely a great white was to blame for the Avalon attack -- 27 great whites had been spotted off Sydney this year.

Click here to read more on this story from The Daily Telegraph.