Nathan Carey (18) was behind the counter when the two men, armed with a handgun, walked into the shop, close to the DART station, at around 8pm.
"They knew what they wanted. It was more than just a snatch and run," Nathan's father Ronnie told the Herald today.
"They took the cash from the till and then brought Nathan out the back and made him open the safe, so they got the day's takings too," he added.
The raiders also took cigarettes before driving away in a dark car towards the DART station. There were no customers in the shop, leading gardai to believe that the raiders had been watching the premises closely waiting for the right time to strike.
There were no shots fired during the raid and nobody was injured.
"We've been robbed before but this went further in that they got into the back of the shop too," said Ronnie.
"They had balaclavas and gloves too, so they seemed organised. And they were calm enough about it," he added.
"It's one of the worst phone calls you can get, telling you there's been a robbery, and Nathan seemed more worried about what was taken, but thank God everyone is okay," Ronnie said.
The family-run newsagents adjoins a creche and an apartment complex and is tucked off the main road.
A garda spokesman said: "The two males were wearing balaclavas and dark clothing. One is believed to have had a firearm.They took a sum of money and cigarettes."
Gardai from Malahide are investigating the robbery and have appealed for anyone with information on the robbery to come forward.
The scene remained sealed off today as gardai carried out a forensic examination.
"I've been in business for 30 years, and we're six years in this shop," Ronnie Carey told the Herald. "These things do happen unfortunately but the important thing is to just try and keep going."