THEY welcomed fans to what they described as "the party of the year" tonight.
And word conquering boyband One Direction didn't disappoint as they performed the first of four Dublin shows at the O2.
It's not at every concert you hear seven and half thousand punters chanting “Mullingar, Mullingar,” but then there's only one act topping the charts right now with a Westmeath man.
Last night Niall Horan was back on home turf and loving every minute of it.
"What's the craic Dublin?" he said as he soaked up the adulation, leading the fans through chants of “Ole, Ole” with bandmates Harry, Liam, Zayn, and Louis.
The majority of acts headlining arenas use elaborate stage-shows, lasers and backing dancers to fill the space.
But One Direction, who have become so big now around the world, they can stand alone on-stage carrying the show through their very presence.
The two hour concert was half performance, half 'An Audience With..’ as the five members answers questions from the audience via twitter.
Such as "What's your favourite theme tune?”
Niall: "Fair City of course" - a reference which would have had fans mystified on any other of One Direction's 117 sold-out dates around the world. Except Dublin.
There seemed genuine affection from his bandmates for dad Bobby Horan who they described as a "great man" before dedicating new single, Blondie cover 'One Way Or Another' to him.
TV presenter Brian Ormond’s daughter Chloe (10) said it had been like “getting a ticket to Willy Wonka's Chocolate Factory” when she learnt her dad had tracked down an elusive pass to the sought-after show the night before the gig.
“I love One Direction, so getting the call from dad was a dream come true for me,” said Chloe.
Katelyn Walsh came from Waterford with mum Claire, aunt Mary Kavanagh and cousin Aimee Kavanagh.
“We're here for Niall. He's one of our own and just fantastic,” said Katelyn.
For many fans it was their first concert and the most exciting night of their lives so far.
They lapped up giant portions of rocked-up pop, killer riffs and soaring melodies which fight to be heard above the screaming.
Niall Horan is not exactly Rory Gallagher, but the Westmeath man did manage to deliver a few guitar solos on a new Fender.
For those who missed out on tickets for One Direction's four sell-out Irish concerts, never fear, there is some consolation in the cameras, which caught most of last night's action for a ‘One Direction 3D’ movie, due out in August.