He walked towards the Matua Dairy at 97 Levers Rd and through the front door after concealing his face with a black mask.
He approached the sole male attendant, who was at the counter using his mobile phone, pointed the pistol at him and demanded cash.
The attendant handed over about $80, which the robber took while still pointing the pistol at his victim and then demanded cigarettes.
The attendant ran out the rear of the shop.
The robber fled towards Ranui St, followed by his victim, who saw him get into a white car on Ranui St. The victim then called the police.
Judge MacDonald remanded the convicted man on electronically monitored bail for sentencing at a date yet to be determined.