Lady Gaga was moved to tears by the appearance of Queen in her audience, during her first concert in Australia.
The pop star kicked off her ArtRAVE: The ARTPOP Ball Tour at Perth Arena on Wednesday night and later admitted she cried during her performance when she saw the band in the crowd and thought of their late frontman, Freddie Mercury.
The English band are also in town for the beginning of their Australian tour which kicks off in Perth on Friday.
Queen's guitarist put out a call on Twitter, after the band landed in Perth on Wednesday, wondering what the band should do for the night.
"Well, where are ya'all, dear Aussies ? Where is the place to be, tonight in Perth? Lady Gaga's Show ? Bri," May tweeted.
The band, along with frontman Adam Lambert, attended Gaga's concert and received a standing ovation from the crowd when the pop star pointed them out from the stage.
Gaga performed her ballad Dope and then touched on the topic of AIDS, before pointing out Queen in the audience.
Lady Gaga told the audience she could feel the presence of the band's late frontman, Freddie Mercury - who died from pneumonia resulting from AIDS in 1991.
The band and the pop star continued the love-in backstage after the show with both Gaga and Brian May posting pictures of the two of them together on their social media accounts.
Gaga admitted in her post that she cried while performing her emotional ballad on stage.
"Me and Brian May from QUEEN. They came tonight to the artRAVE and I'm so PROUD of Adam Lambert singing with them. Made me cry during Dope when I saw them all sitting there. I thought about Freddie," Lady Gaga posted on Instagram alongside a picture of herself with Brian May.
The pop star seemed to have embraced a 1980s inspired style, wearing a curly, black wig, fishnet tights and a black T-shirt, which she was wearing in the backstage shots.
May also posted a shot of the two performers together on his twitter account.
"Reunited with a dear pal tonight @ladygaga - this girl is one of the great artists of our lifetimes. Bri X," he tweeted.