(CNN) -- He claimed he won the prize this week, and now it's official: Pedro Quezada of New Jersey is the winner of Saturday's $338 million Powerball jackpot, the New Jersey Lottery said Tuesday.
Quezada announced on Monday that he held the winning ticket, but the final word from lottery officials didn't come until Tuesday.
"I felt pure joy, just happiness," Quezada, a Dominican immigrant and deli owner, told reporters at a news conference Tuesday.
"It's a gift from God," he said.
Undoubtedly, his life will change. But the money "won't change my heart," Quezada said.
He said he was walking to work Monday and saw a crowd at a liquor store in Passaic, New Jersey. He'd bought his Powerball ticket there, so he thought he should go in to see who won. He had his ticket with him, and showed it to the clerk, who checked it and told him he was the winner.
Laughing, he recalled leaving the store and going to "hide." He said he was nervous Monday night. "I couldn't close my eyes," the father of five said in Spanish, relying on a translator throughout the news conference.
"I never thought I would win such a prize," Quezada said.
Quezada chose the up-front cash option, instead of an annuity, when he bought his ticket. The lump sum is $211 million. But after federal and state taxes, he will net about $151 million, Carole Hedinger, executive director of the New Jersey Lottery, has said.
One reporter asked whether he planned to stay in New Jersey, while others inquired whether he wanted to return to the Dominican Republic to celebrate with family and friends. Quezada said he moved to the United States when he was 19.
"I don't know," he said. "I have to think about it, my mind is not clear yet."
When asked if he plans to keep working, he said no, recalling long days that started at 5 in the morning. And his son who works at the deli won't continue either, Quezada said.
"Of course, my family's a very humble family, and we're going to help each other out," he said.
Quezada is married and has five children, ages 5-23, and one granddaughter. His wife, who is from Mexico, also spoke at the news conference, saying she didn't have words when her husband first broke the news.
Quezada said he might buy a car with part of his winnings.
A reporter asked him what kind of car he has now. "My feet," he answered, laughing.
He said he wants to help people with his winnings. "I don't know exactly how, but I will help those in need," he said.
Quezada's ticket matched all six numbers drawn Saturday night: 17, 29, 31, 52, 53 and the Powerball, 31.
The largest jackpot in Powerball history was $587.5 million. The lottery is held in 42 states, the U.S. Virgin Islands and Washington.
CNN's Dana Ford and Stephanie Gallman contributed to this report.