Headliners Queen + Adam Lambert re-enacted the original band's 1985 Live Aid performance at the Fire Fight Australia concert.
Tens of thousands of people have poured into Sydney's ANZ Stadium for a star-studded relief concert, raising close to $10 million for those affected by the summer's bushfire crisis.
Organisers said 75,000 people attended the Fire Fight Australia concert on Sunday, which they said sold out within 24 hours of tickets going on sale.
Hosted by comedian Celeste Barber, who has raised more than $50 million for bushfire relief, all ticket profits will go to groups which are helping fire-ravaged communities get back on their feet.
Barber became emotional when she thanked the volunteer firefighters who sacrificed their time to battle devastating blazes, saying "you will never know how grateful we are".
"Our volunteers across this entire country, they are the ones who saved us," she said.
"They are the ones who cancel holidays to stay here and look after us, and I will speak now very confidently on behalf of a nation when I say to those volunteers: Thank you."
Barber also fired a shot at government handling of the bushfire crisis.
"It's been such a hectic time. As Aussies, we bear together and look after each other - because it turns out the people at the top don't," she said to cheers from the crowd.
Rock behemoths Queen + Adam Lambert played to a roaring crowd, with Alice Cooper, Irish favourite Ronan Keating and singer-songwriter k.d. lang also on the line-up.
Lambert said their involvement was a "no-brainer" while Keating, whose brother-in-law is a volunteer firefighter in Queensland, flew into the country especially for the concert.
"I wanted people in Australia to know that we heard you, and that you weren't alone," Keating said.
"That was really important to me, that I could be here and perform or do whatever just to stand in solidarity."
Andrea Gartside decided to attend the nine-hour concert with her friend Maureen Mackie to support the firefighters after the unprecedented fire season.
"We're doing our part in helping," she said.
"It's going to be awesome ... it's great that it's bringing everyone together for a good cause."
Queen fan Cheryl Hind was excited to see the band perform again.
"It's part of why I'm here today and to thank the firies for everything they've done," she said. "It's just amazing."
Lisa Yasso travelled from central Queensland to see the legendary rock band perform again.
"It's an awesome cause," she said.
Popular Australian acts spanning generations are also on the line-up, including 5 Seconds of Summer, Amy Shark, Daryl Braithwaite, Delta Goodrem, Grinspoon, John Farnham, Lee Kernaghan, Baker Boy, Olivia Newton-John and more.
Fire Fight's profits will be shared between the Red Cross' disaster relief and recovery fund, rural and regional fire services and the RSPCA's bushfire appeal.
Donations to the Foundation for Rural and Regional Renewal will also be accepted during the concert, to fund grants for community-led projects needing support in the bushfires' aftermath.