After fleeing in the woman's car, the man then attempted a second robbery at Knighton Road Dairy on Knighton Rd in Hillcrest.
Neilson said the man again demanded cash but when he got nothing, he fled.
Police chased the car for a short time from Silverdale, before abandoning the pursuit.
The stolen car was later found dumped at a property in Morrinsville.
Neilson said inquiries were continuing to identify and try to locate the man.
The two retailers and the woman from the vehicle were not injured.
He is described as Maori or Polynesian man, of solid build and was wearing a blue overalls over a grey hoodie.
Anyone with information can contact Hamilton police on 07 858 6200, or Crimestoppers anonymously on 0800 555 111.