Mr Ah Chong said he expected the customers from the Kensington Countdown to also use the new store and its presence in the Regent would attract plenty of new customers.
Regent New World owner Todd Leathem said the competition could only be good for shoppers.
"We welcome competition as good for the area and for us it will bring even more customers into the area and it will give Countdown customers a better experience in their store," Mr Leathem said.
"I'm looking forward to it and the customers will be too. Probably the only problem could be the extra traffic that it will bring."
The expected extra traffic load on Manse St and neighbouring Wallace St has some residents concerned.
Meanwhile, Mr Ah Chong said he was pleased the store was finally opening after several months of construction work.
"There is always a bit of nerves there when doing something like this, but I'm looking forward to bringing a whole lot more customers through the doors."
The new store will employ 87 people, up from the almost 80 in the Kensington store, as well as 20 temporary staff who will go on to work on Countdown's Paihia and Dargaville stores.
Mr Ah Chong said the new store was almost twice the size of the Kensington store it was replacing.
Countdown is owned by Australian-based Progressive Enterprises, while New World, Four Square and Pak'n Save are run by New Zealand-owned Foodstuffs.