Pop diva Katy Perry had a surprise for those attending her Nokia Theater concert in LA last week: a duet with special guest Rebecca Black. It was a Friday night, of course.

Looking like she'd sprayed herself with glue and rolled around in a pile of cotton balls, the 'California Gurls' singer trotted out the internet phenom to ... silence? The crowd didn't seem to recognize Black initially, but when Perry introduced her, fans finally roared their approval and sang along to a mercifully brief version of Black's viral hit 'Friday.'

When they were finished, Perry proclaimed, “That was our moment,” making reference to Black's newest single, 'My Moment.'

This isn't the first time Katy has shown the young singer some love -- the teenager also appeared in Perry's music video for 'Last Friday Night (T.G.I.F.).'

When Black left the concert stage, Perry declared, "Dammit, I love the internet."

[via PopCrush]

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