The winner of the $758.7 million Powerball jackpot, the largest grand prize ever won on a single U.S. lottery ticket, came forward Thursday to claim her prize.

"My pipe dream came true," Mavis Wanczyk, of Chicopee, Mass., said at a news conference Thursday afternoon.

Wanczyk, 53, is a hospital worker who said she had hoped to retire in 12 years.

"I called them and told them I will not be coming back," she said with a laugh.

She said she and a co-worker were checking their numbers last night when she realized she won. She said she was so rattled she was nervous about driving, and the co-worker followed her home.

Her fortune began to sink in Thursday, she said.

"I have come down from all that," she said. "I just want to be alone, be me, and figure out what I want to do."

Wanczyk, who chose to take a lump sum of $480 million before taxes, bought the ticket Wednesday afternoon at a Pride market in Chicopee. Hours earlier, at around 2:30 a.m. Thursday, the lottery agency had said the winning ticket was sold at a convenience store outside Boston.

The initial announcement sent a flock of media to Handy Variety in Watertown. Handy Variety owner Kamaljeet Kaur took the updated news pretty well, considering she had been set to collect $50,000 for selling the big winner.

“I’m OK ... still happy,” she told The Boston Globe. Her solace: The store will receive $10,000 for selling a $1 million winning ticket.

State lottery Executive Director Michael Sweeney apologized for the confusion. He blamed the confusion on a transcription error when officials manually recorded the dealers that sold the big winner and two other retailers that sold $1 million tickets.

Bob Boduc, who owns the Chicopee store, said he didn't find out his store sold the ticket until he started getting calls from national networks. He said, based on information from lottery headquarters and store cameras, the ticket apparently was sold to a middle-age woman at about 2:30 p.m. ET on Tuesday. He had no other details.

He said he would contribute the store's $50,000 to local charities.

"It's really pretty amazing," he said. "It could have happened anywhere in the country. It's really a stroke of luck."

The winning numbers: 6-7-16-23-26 with a Powerball of 4

The prize was the second-largest Powerball payout in history, behind a $1.58 billion payout in 2016 shared by three winners. The drawing Wednesday night snapped a string of 20 in a row without a Powerball jackpot winner.

In addition to the big winner, almost 1 million other hopefuls will come away with something from the drawing. Six people won $2 million each and 34 more won $1 million.Grand prize winner aside, 9,397,723 players won more than $135 million, lottery officials said.

According to a story last year on Business Insider, there are a total of 292,201,338 possible Powerball combinations, making the odds of winning 1 in 292,201,338.00. So, at $2 a ticket, it would cost someone $584,402,676 to buy every possible combination.

Of course, if you could lose a lot of money if you had to split the jackpot with, say, four others who tried the same method. And there are taxes to worry about, too.

The overall odds of winning any prize from one $2 ticket are 1 in 24.87.

There have been two other Powerball jackpots of at least $430 million this year. A jackpot in June reached $448 million, while another in February was worth $435 million.

The jackpot for Saturday's drawing drops to a mere $40 million. Powerball is played in 44 states, Washington, D.C., Puerto Rico and the Virgin Islands.