More than 45,000 tickets for Madonna's open air concert at Slane Castle, Co Meath later this summer were sold on the opening day of sales yesterday.
Mr Justin Green, of the promoters MCD, said: "We are very happy with the number of tickets sold. To sell almost 50,000 tickets in one day is better than we expected.
"There is no doubt the concert will sell out - it is just a matter of time."
It was confirmed last night that English rockers, The Darkness, are to support Madonna at the Slane concert on August 29th. So too is Iggy Pop.
It will be the first time Madonna has played in the Republic. There is capacity for around 80,000 fans.
Total ticket sales are estimated to reach €7.1 million if the event sells out.
Madonna, currently on the US leg of her Reinvention Tour, is in the middle of a six-night run at Madison Square Garden in New York.
Slane will be the only outdoor show on her tour.
Meanwhile, the Missy Elliot concert scheduled to take place at Dublin's Point Theatre on Thursday, June 24th, has been cancelled due to unforeseen circumstances.
It is not possible to reschedule the concert and tickets can be refunded from points of purchase.