A week earlier that planned, Katy Perry has released the first single from her upcoming album, Prism. 'Roar' is already feeling the benefits of the early release too, with the singer seeing her single shoot straight to number one in the iTunes chart in the UK as her fans came out in their droves to catapult the first single from the album to instant success.

Katy Perry VMAs
Perry performed the single at the recent VMAs

See all this red carpet pictures of Perry at the VMAs

Released on 1 September, the track only needed a few hours to cement itself atop the iTunes chart, knocking Ellie Goulding's 'Burn' to the number two spot after two weeks atop the chart. Over in Perry's native United States, the single has fared almost as well, stalling at number two on the US Billboard Hot 100 at the time of writing. But with time differences to take into account, there is a good chance that Perry will be number one before the day is over.

Perry was keen to show her appreciation at the single's massive success and tweeted "YAY UK! A week early & by popular demand you can be louder than a lion! Finally, It’s your turn to ROAR!" following the immediate success of the track.

The singer, who performed the new single as part of the recent MTV Video Music Awards, will also be closing the month-long iTunes Festival at London's Roundhouse Theatre on September 30, where she will probably be debuting a number of new tracks as well as 'Roar.'

Prism (a title that is still a little odd to us given the whole NSA scandal), will be released on October 22.

Katy Perry Grills
The singer shows her teeth in the new track

Katy Perry teeth
Her new album arrives next month