Police said the man forced one of the employees to open the till and place money into a bag. He then assaulted the employee and fled the store through the back door into Marlborough Park.
A police dog unit tracked the man on to Edgeworth Rd, where he was witnessed by a member of the public getting into a white vehicle and fleeing the scene.
North Shore police would like to hear from anyone who may know anything about the incident or may recognise the man from the CCTV footage.
The man is described as 1.75m to 1.83m tall, of thin to medium build and wearing dark clothing, black and white Chuck Taylor-style shoes, and a black balaclava.
Anyone with information is asked to contact Detective Alan Welch on 09 213 7797. Information can also be provided anonymously to the Crimestoppers organisation on 0800 555 111.