A lucky person who bought a ticket at a gas station in Des Plaines outside Chicago won the third-largest lottery jackpot in US history.

What's more, the person's winnings were even bigger than expected when lottery officials on Saturday revised the payout amount up to $1.337 billion (€1,307 billion) from an estimated $1.28 billion.

According to US government data, the odds of winning the Mega Millions jackpot are one in 303 million, much higher than the one-in-a-million chance of being struck by lightning.

"We're eager to find out who won and look forward to congratulating the winner soon,'' Ohio Lottery Director Pat McDonald, the current Lead Director for the Mega Millions Consortium, said.

Full lotto payout could take decades

Hard as it may be, the winner won't be able to blow the $1.337 billion all at once.

The prize is only for winners who choose the annuity option, paid annually over 29 years. Most winners opt for the cash option, which for Friday night's drawing was an estimated $780.5 million.

Lottery payouts in the US is taxed, so that will also gobble up a significant chunk.

The winning ticket may have also been bought by a group of people.

"We won't know whether it's an individual or it's a lottery pool until the winner comes forward to claim their prize,'' National Mega Millions spokeswoman Danielle Frizzi-Babb said.

The ticket holder has a year from the drawing to claim the prize, and can choose to withhold his or her name from the public.

Friday's total falls short of the record of $1.586 billion, set in January 2016 by America's other national lotto, the Powerball, though that sum was split among three winners.

The second-highest prize ever was in an October 2018 Mega Millions drawing for $1.5 billion.

As of Saturday afternoon, no winner had come forward.