"I was banging on the doors and windows so hard," Mr Kim said.
"They came out the bedroom window, [and] when the window opened all the smoke came out. Maybe another 10 minutes [inside] and they would have been killed by the smoke."
Mr Kim also warned firefighters about two large gas bottles outside the rear of the shop.
"[The fire] was very close to the gas bottles," he said.
Mr Kim, who has owned the bakery for 10 years, said he did what anyone would have done in the situation. Neither the business or home had working smoke alarms.
Mr Xu remembers waking up to Mr Kim's frantic knocking on windows and doors. "I saw lots of smoke, black smoke. I couldn't see any fire at that time," Mr Xu said. He only bought the business in April, and had insurance for the damage.
Waipu deputy fire chief Alan Vaile said two engines came from both Waipu and Ruakaka stations to battle the blaze. Fire-fighters had to smash to glass sliding doors to enter, he said. "It was a really good save by all the fire-fighters, who prevented it spreading to the living quarters," he said. By the time fire safety officer Mr Bain arrived at 7.15am, the fire was contained. "These guys were very lucky."
" If this was at 2am or 3am [when people would not have noticed the smoke it might have been a different kettle of fish," Mr Bain said.
He praised Mr Kim and Mrs Siv for their efforts. "They did a mighty job in rousing the occupants - they have to be commended for what they did."
It provides a timely reminder for people to have working smoke alarms.
Meanwhile, a house has been moderately damaged in a after a stove fire on Raewyn Street in Morningside on Monday night.
- Additional reporting AUT student Allie McPhee