Mrs Patel said the store sold a Second Division winner last month worth $29,554, but this was the first First Division winner since they took over.
Powerball was not struck on Wednesday and has rolled over to Saturday where the jackpot will be $38 million.
"If a single player is lucky enough to win the top Powerball prize on Saturday night, it will be the single largest prize ever won in New Zealand," Lotto spokeswoman Emilia Mazur said.
Strike Four also rolled over and will be worth $500,000 on Saturday. The winning Lotto numbers were 2, 9, 13, 25, 29 and 36, with the bonus number 11 and Powerball number 6. The Strike numbers were 29, 25, 9 and 36.
While Wednesday's First Division win was the first for the Patels, their store is the second-most successful in Northland having sold 16 First Division winners, behind Dargaville's Mags N More with 17 and ahead of Civic Video & Lotto Kerikeri with 14.