The store owner has received a $1m (£880,000) bonus for selling the winning ticket in Altadena, California.
The grandfather of 10 - who arrived in the US from Syria in the 1980s - said he was excited but would return to the shop as usual at 06:00 every morning.
One ticket scooped the $2.04bn jackpot, according to Powerball.
Mr Chahayed said he did not know who had bought the ticket, but hoped it would be someone local.
As for his own plans, he said he would help his children.
"My son is expecting a baby in two months, so we are excited!" Mr Chahayed said, according to the BBC's US partner CBS. "We can have a nice celebration for another baby."
"All what I do, I work hard, seven days a week," he told the news outlet.Tuesday's jackpot was the world's largest lottery prize.
The odds of winning it were set at one in 292.2 million, according to Powerball.
Powerball tickets cost $2 to buy, and a winner can choose to receive a lump sum payment - which almost every winner goes for - or the full jackpot amount in an annuity paid over 29 years.
If the winner of Tuesday's record draw opts for a cash pay-out, they will take home $997.6m in one lump sum before taxes.