"It's been a wonderful day for us as well, even though we didn't get the $20 million in our bank, it's still very exciting for us."
The store, which Mrs Sinclair and her husband have owned for 15 years, has had a number of winners in the past, but never any as big as this one.
When these ticket-holders claim the prize, they'll be the ninth multi-millionaires this year, said NZ Lotteries chief executive Wayne Pickup.
"A win this big is simply life changing, no matter what your situation - so no doubt they'll be celebrating."
The total prize was made up of $500,000 from Lotto first division and $20 million from Powerball first division.
Another lucky Lotto player from Christchurch also won a $500,000 share of Lotto first division. Their winning ticket was sold at Unichem Bishopdale Pharmacy in Christchurch.
Read more: Manukau 'luckiest' place for Lotto