The robber with the pistol pointed it at the owner and calmly told him to "just put the money in the bag", while the other man held large kitchen-type knife.
Mr Singh said his boss smashed a lolly jar on a shelf and ran towards the till. He picked up a long wooden stick and slammed it down on the counter.
The gun-wielding robber held the McDonald's bag out and demanded cash, but the owner snatched the bag off him and yelled at the two men to get out of his store.
Mr Singh said he tried to remain calm.
"My first concern was for the owner. My attention was totally focused on the gun and the man with the knife."
Mr Singh picked up a hammer and raised it above to his head to try and scare them off.
The owner chased the men out of the shop, who ran off down Carlisle St, then Tyrone St.
Police said the robbers were last seen getting into what was described as a modern silver car.
Store manager Karan Chawla, who was not there at the time of the robbery, said the owner told him he had been frightened during the ordeal, which was over in less than a minute.
"When I heard, I got scared too and immediately thought 'what if my owner or I had been working in the store alone', they could easily have hit me or shot one of us if it hadn't been a plastic gun. We have two people working in the store every day now for our own safety.
"I was angry too. How dare these people come to our store and try to rob us when we work so hard to make a living."
Mr Chawla said robberies seemed happening almost every day and store workers should be able to protect themselves.
Anyone with any information about the robbery should phone Tauranga police on 07 577 4300, or alternatively anonymously phone the Crimestoppers line on 0800 555 111.