Katy Perry is the new champion of the singles chart this week! Her 'ROAR' knocked out Robin Thicke's 'Blurred Lines' to earn the No. 1 spot on the latest Billboard Hot 100. Robin's mega hit, which topped the tally for the previous 12 weeks, falls to second place. Eminem's 'Berzerk,' meanwhile, enters the chart at No. 3.

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'ROAR' is the lead single off her upcoming third album, 'Prism,' which is due Oct. 22. The track also tops the Digital Songs and On-Demand Songs tallies, and has been named the week's top Airplay Gainer.

And don't forget: The much-anticipated 'ROAR' music video drops tomorrow (Sept. 5) -- in Junglescope (whatever that is)!