So Perez Hilton was right when he said Katy Perry's "Roar" is more interesting than his friend "Lady Gaga's" single "Applause." "Roar" - the first single from Katy's upcoming album "Prism," has reportedly sold 557,000 downloads in its first week, topping the digital song chart and scoring the highest sales week of the year, according to Nielsen SoundScan.

Both the singles - "Roar" and "Applause" were released on the same time. Katy has pegged huge first-week numbers with "Roar' that are not only the best of 2013, but of her career too. The single surpassed 509,000 downloads in first week!

"Roar" surpassed "Firework" (which sold 509,000 copies in December 2010) to give Perry her biggest digital-song sales week ever, MTV has reported.

According to Billboard, other tracks to reach near Katy Perry's total were Flo Rida's "Right Round" with 636,000 in 2009, Ke$ha's "TiK ToK" with 610,000 in 2009, Bruno Mars' "Grenade" with 559,000 in 2010, and Taylor Swift's "We Are Never Ever Getting Back Together" with 623,000 in 2012 and "I Knew You Were Trouble" with 582,000 in 2012.

"Roar" also marks Katy's biggest digital song debut by the pop superstar, surpassing "Part of Me's" 411,000 downloads in 2012.

In comparison, Lady Gaga's "Applause" is currently at No. 3 position with 218,000 downloads; lagging behind the Robin Thicke's "Blurred Lines" tune sitting at No. 2 with 291,000.

Perry's "Prism" is due to release on Oct. 22, while Gaga's "ARTPOP" is due Nov. 11. The two artists are performing on Sunday's MTV Video Music Awards show, with Gaga opening and Perry closing the show.

Gaga has gone to great lengths to promote the single "Applause" from getting semi-nude in the video to appearing with the colourful artwork on her face. She even got engaged in a Twitter war with celebrity blogger Perez Hilton who called her album a flop and praised Katy Perry's "Roar."

In comparison Perry released a picture of the very unique and fresh artwork for her long awaited single "Roar" on Twitter and is promoting the album very quietly. The singer is seen wearing a dark blue jacket with a lion embossed on its back side. The singer looks toned down with black hair and pick lip color.

Looks like the Katy Perry - Lady Gaga battle has a winner today. Perry has proved her worth and achieved her career's high.

But for all you Gaga fans, the singer will always be a winner in their hearts for her queer sense of style and Gagaisms.

Hear "Roar" here

Hear "Applause" here

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