The winning ticket for the €19 million lotto jackpot prize was sold in Co Mayo.
The numbers drawn were: 2, 9, 16, 30, 37, 40 and bonus number 23.
The winner of the lotto has not yet come forward, and the National Lottery has appealed for people to check their tickets.
Fran Whearty, Communications Executive with the National Lottery, said the shop where the ticket was sold would be named later in the week.
He gave this advice to the winner: "Take a deep breath it's a massive amount of money. You need to sign the back of your ticket which essentially makes you an owner of the ticket.
"Just take a couple of days but definitely get in touch with us."
Last night's draw was a must-win affair after more than seven months without a jackpot winner.
The jackpot had not been won since 9 June, and was capped at €19.06m since early October.
In addition to the winner, there were also 149 match five bonus winners, who shared nearly €5.5 million.