A health care worker in the United Sates has won $US750 million ($NZ1.04 billion) in a Powerball drawing - the largest prize for a single ticket-holder in the contest's history, Massachusetts lottery officials confirmed.
Mavis Wanczyk (53) from Chicopee appeared at an afternoon news conference to claim her prize on Thursday.
"I wanted to get this over and done with, and then everyone would leave me alone," Wanczyk, the mother of a 31-year-old daughter and a 26-year-old son, told reporters.
Wanczyk said she had worked for the past 32 years at a Springfield hospital, but added: "I've called them and told them I will not be coming back."
Powerball said on its website that the single ticket matched all six numbers drawn on Wednesday night: 6, 7, 16, 23, 26 and the Powerball of 4.
Wanczyk said she learned of her win when a colleague encouraged her to check her ticket as she left work.
"I said: 'I know it's never going to be me; it's just a pipe dream,'" Wanczyk said, adding that she was shocked to find "I am a winner."
The winning ticket was sold at a Pride convenience store in Chicopee, which is located about 145km west of Boston, according to the Massachusetts State Lottery.
The owner of that store plans to donate to charity the $US50,000 prize he will receive for selling the winning ticket, the commission's executive director, Michael Sweeney, told reporters.
The state lottery had originally said the winning ticket was sold in Watertown, a suburb of Boston, but corrected its announcement hours later.
"This was the result of a human error," Sweeney said. "Our internal systems, and I want to be clear about this, our internal systems always had the correct information."
Wanczyk will have a choice of receiving annual payments totaling $US758.7 million over 29 years, or a lump sum of more than $US440 million, before taxes.
Beyond retiring early, she did not say how she planned to spend her winnings.
The odds of a ticket having all six winning numbers are 292.2 million to 1, according to the Multi-State Lottery Association.
Powerball tickets are sold in 44 U.S. states, and Washington, D.C.; Puerto Rico; and the US Virgin Islands.
No one had won the Powerball's top prize in the twice-weekly drawings since June 10, when a California man won $US447.8 million.
