The Tiebtienrats purchased Suk Jai last September, after their restaurant in central Christchurch, Thai Smile, was destroyed in the earthquake.
"Mum just loved this restaurant when she saw it," Charn said.
Their chefs also made the move north with them.
Seven months after business in Whangarei began, mystery diners visited from the Thai prime minister's office, and shortly after placed a call acknowledging the quality of their food.
The Tiebtienrats collected the award at a national prize-giving in March in Auckland, and it is now proudly displayed on the wall of their restaurant.
Charn said business has been good and Whangarei is a great location.
"It is very nice, because Whangarei is a small town and when I walk in the city I recognise customers," he said.
His mother, Anong, agrees.
"Customers are nice and being a small town people remember us. Whangarei is like a family."