Ronan Keating, Shane Lynch and Mikey Graham flew home to Dublin on Saturday to attend dad-of-two Keith's annual masquerade ball in aid of Irish Autism Action.
The red carpet was rolled out at the five-star Powerscourt Hotel, Co Wicklow for the black tie gala, with a string of celebrities attending. Off his crutches for the first time since surgery, soccer legend Robbie Keane turned out with his model wife Claudine.
They were accompanied by Brian Ormond and Pippa O'Connor, as well as Brian McFadden and Vogue Williams.
Retired Manchester United star Paul Scholes, a close friend of Keith's and his wife Lisa, came with his other half Claire.
Despite being "absolutely shattered", Boyzone happily entertained over 400 guests with Imelda May also performing. The event raised a staggering €100,000.
"We've been double jobbing for the past few weeks because we're promoting our album and then playing to crowds every night, so we're wrecked," Keith told the Herald.
"This is the lads' only day off so I'm honoured that they came home to support the night, it means a lot to me."
Keith, whose daughter Mia (13) is autistic, added: "This is something I'm involved in for personal reasons so that has its added pressures."