Just after midnight, two men with their faces concealed confronted the 63-year-old while he was working at the service station on Canterbury Road and threatened him with a knife, demanding cash.
They attempted to kick in the office door and continued to threaten the attendant, before he handed over money and they ran off.
Detectives are working in the area to identify the men and are calling on members of the public who may have dashcam or CCTV footage from their business to help identify the offenders.
Detective Inspector Andrew Mackay said that in many of these violent offences the offenders preyed on those that were vulnerable.
“The very small gain is minimal compared to the years in jail they will face,” he said.
Both men are described as being about 175cm to 180cm tall, and wearing a black face covering.
One was of slim build and wearing a green hooded jumper, navy tracksuit pants and white shoes, while the other was of solid build and wearing a black hooded jumper, black tracksuit pants and black shoes.
Anyone who can help with the investigation is urged to contact Campsie Police or Crime Stoppers on 1800 333 000.
