Lottery officials say 50-year-old Mahendra KC was standing outside their South San Francisco offices the minute they opened their doors Wednesday morning.
Mahendra bought his $1 ticket at Huntington Liquor in San Bruno.
According to his family, the taxi driver had been thinking about winning it big since immigrating to the Bay Area from Nepal about a decade ago.
"It's just a life-changing situation here," said daughter Chandani, who was helping translate for her father. "Now whatever dreams we always had all together as a family, they're going to be true."
Mahendra's children say it's still too early to predict whether their parents will keep both of their jobs. Mom currently works as a housekeeper at a San Francisco hotel.
"We haven't decided," Chandani said. "We're just kind of really over-excited right now. We're not thinking of anything else."
Son Niranjan says the family plans to use some of its winnings to seek organ transplants for their grandparents, and to have his dad Mahendra's chronic heart problem addressed. They hope to use the rest of the money to pay off school loans.
"You know, we've worked so hard throughout our life. That's all my dad thinks about is winning the lottery. Hopefully our lives change now. It's pretty much an (American) dream come true," he added ? still in disbelief.
Two tickets sold in Florida and Maryland matched all six numbers. They'll split the $400 million jackpot -- the sixth largest lottery prize in U.S. history.
The store owner in San Bruno will get $10,000 for selling the ticket.