The Wanted are the bestselling British boyband in the US since 1995.
Dubliner Siva and bandmates Max George, Jay McGuinness, Tom Parker and Nathan Sykes celebrated reaching the No 4 spot on the official Billlboard chart in the Irish capital.
After performing to a sell-out crowd at the O2 arena and an appearance on the Late Late Show, the Blanchardstown native and his pals took to trendy hotspot Lillie's Bordello, where they partied with friends and family into the early hours, to mark the end of their world tour.
While Siva (23) and the boys jetted back to the UK this morning, a source told the Herald that he was delighted to catch up with his family and girlfriend Nareesha McCaffery.
A pal of the former model told the Herald that Siva couldn't wait to catch up with his "two favourite brothers" Kelly and Daniel.
"This gig was really important for Siva, he doesn't get to come home that often, so he was so looking forward to performing in his hometown -- and to play in the O2 is such a memorable experience. Many of his relatives were in the audience last night, including aunt, uncles and cousins -- it was a big family event."
The singers booked out the entire VIP area of Lillie's for their trendy wrap party in town.
An insider revealed that more than 150 people on the guest list arrived for the private bash and security was extra tight to ensure the band could really relax and enjoy themselves, after turning up with their team.
Their tour manager requested unlimited champagne for the night and attendees were greeted with drinks upon arrival.
Bosses at the celebrity hotspot confirmed the group's support bands Parade, Lawson and Fanfair also made an appearance and it is believed that Coronation Street star Michelle Keegan flew over to celebrate with band member Max George, her fiance.
The chart-toppers are expected to take off on a second stint in America later this month and will make an appearance on the Jay Leno Show, before flying out to Las Vegas for MTV's famous Spring Break.
Earlier this week, The Wanted broke all previous records by a UK group, to climb to the No. 4 spot on the Billlboard chart, beating previous title-holders Take That -- who reached the No. 7 position in 1995.
The group blasted the US Billboard Hot 100 Chart with their hit Glad You Came, a Number One in the UK, officially making them Britain's most successful boyband. It comes after the band went to number one in the US and Canadian iTunes chart.