Snow Patrol were back home, completing the hat-trick after their Ward Park gigs in 2007 and 2010. They burst on stage for Ward Park 3 to a loyal and receptive crowd who, after the first song, held up signs saying "we love you".
And while the rain stayed away, it was Lightbody who admitted he was under the weather, as he announced he had woken up with a "stinking cold".
He asked the estimated 35,000-strong crowd would they be able to help him with some of the singing - an invitation they were more than willing to accept.
But if he hadn't mentioned it, it's doubtful you would have noticed as they soared through hit after hit, blending the classics with material from their latest album Wildness.
Gary told the crowd: "Thank you for coming to Ward Park 3.
"The first Ward Park had 30,000 people and Ward Park 3 has 35,000 people at it.
"We've been away for a long time but we are back now."
During Take Back the City, they paid tribute to murdered journalist Lyra McKee, with her picture projected on the screen during a video montage, as well as images of campaigners at a same-sex marriage parade in Belfast carrying a cutout of her name in rainbow colours.
There was also a surprise appearance from U2 frontman Bono who came onstage to sing their hit One.
Lightbody introduced the song saying, "there is one song that says everything we need to in these heady times".
Social media was quickly alight with concert-goers in disbelief that Bono had turned up.
Gary later paid tribute to the host of Northern Ireland talent that had preceded them on Saturday's one-day festival bill, including Two Door Cinema Club, Foy Vance and Ash.
A second stage showcased the future of the Northern Ireland music scene, featuring JC Stewart, The Wood Burning Savages, Kitt Philippa and ROE. A dazzling light display accompanied the show and an encore of the haunting What If This Is All The Love You Ever Get, and the rousing Just Say Yes completed the night.
Posting on social media the gig, Gary said it was a night they would never forget.
He wrote: "To sing One with Bono was like a billion birthdays all rolled into, well, one. I'll never forget it. And we'll never forget today. All of it. Loads of love. Thank you Bangor."