Montreal, Canada - Billie Eilish thrilled fans at Osheaga Festival over the weekend as she welcomed Armani White on stage in a surprise performance of his viral song named after the singer.

During Eilish's headlining Saturday set at the Canadian music festival, the 21-year-old asked the crowd, "You know that song that's like, 'Glock tucked, big t-shirt, Billie Eilish?' You know that song?'"

Sure enough, the track's instrumental soon kicked off before White himself ran onto the stage.

The 26-year-old's energy was electric as he performed the song with Eilish alongside him.

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White uploaded the full video of the performance on Tuesday, giving fans a close look at the epic team-up.

According to Rolling Stone, the pair had just met for the first time at the festival.

The song's viral success earned White a record deal, and he explained that Eilish is someone he idolizes in the music industry, ultimately inspiring the mega-hit.

Speaking with Genius in 2022, the rapper explained that he hopes to be an "anomaly" in hip-hop in the way Eilish is one for the pop sphere.

"To just be in this world but completely stand out from everyone else, I think that's a lot of the significance behind the record," White said.

White gushed over Saturday's performance on Twitter shortly after, writing, "I have never heard that many people scream in my f***ing life hahaha Billie Eilish has an army!!"