The former Oasis star was joined by the Britpop group's guitarist Bonehead at the fundraising concert - but despite rumours of a reconciliation with Noel, his brother wasn't invited.
Liam performed both his old classics including Rock ‘n’ Roll Star and Morning Glory, as well as brand new material.
Discussing the state of today's music industry, Noel, 50, lashed out at the former One Direction singer's solo effort.
Liam's first solo album As You Were is due out later this year, accompanied by a North American tour that begins in November.
Stage hands can also be seen dismantling the stage just moments after they realised the frontman would not be returning.
According to Globo news website, Liam was in the middle of his fourth song, Greedy Soul, a forthcoming release, when he exited the stage.
Noel Gallagher is almost as well known for his scathing put downs and he is for his Oasis anthems.
In his latest outburst, Harry Styles and Simon Cowell both came under fire from the acerbic Gallagher elder.