The winning numbers are 13-23-27-28-32-45, according to the company's website.
This is the sixth winner of the Mega 6/45 since mid-October. The value of previous top prizes ranged from US$2.4 million to more than US$4 million.
Vietlott on December 5 officially expanded to Hanoi with 150 agents, hoping to replicate its success of the past few months in the country’s south.
The company’s sales revenue rose 4.6 times in less than two months, to VND734 billion (US$32.1 million) as of November 20, from just VND159 billion on September 30.
Sales for the Mega 6/45 alone were VND730.5 billion (US$31.9 million), or 99.5% of the total revenue.
In January, Vietlott signed an exclusive 18-year contract with Malaysian conglomerate Berjaya to launch computerized lottery games.
The Mega 6/45 is the company's first foray into the market. Players select six numbers from 1 to 45 and win a jackpot that starts at VND12 billion (US$538,000) by matching all six numbers from the draw. Each ticket costs VND10,000 (40 cents).
The prize will keep growing until there is a winner. The odds of winning have been estimated at around one in 8.14 million.
Vietnam generally does not allow its citizens to gamble, but lottery tickets are popular across the country.
Traditional lottery tickets in Vietnam have predetermined numbers printed on them, with the highest prize set at VND1.5 billion (US$65,900).
Facing tough competition from Vietlott’s Mega game, the companies behind these traditional tickets have decided to raise the top prize by 33% to VND2 billion, starting next year.