Katy Perry roars to iTunes album chart summit with Prism after X Factor performance

But the star's appearance did little to improve X Factor ratings

Katy Perry performs on The X Factor 2013 (REX/Tom Dymond/Thames)

Her performance on The X Factor may have sounded more flat than fierce, but that hasn’t stopped Katy Perry’s album roaring in the charts.

Perry’s new album Prism has risen to the top of the iTunes chart following her X Factor appearance, which saw her perform her new single “Roar”.

The single, which held the number one spot for two weeks on the UK Official Singles Chart, has also risen to number four on the most-downloaded iTunes songs chart. It was in sixth position in yesterday's countdown.

Perry’s appearance, however, did little to improve The X Factor’s live results ratings, which saw Shelley Smith sent home by the judges

The show, which has been suffering against Strictly Come Dancing, was watched by 8.9 million viewers, down 600,000 on last week.

Saturday’s X Factor live show received the poorest ratings of the series so far.

An estimated 7.9 million tuned in to watch the acts perform, down 1.2 million on last year’s equivalent episode and down 2.5 million on 2011’s equivalent show.

Last night’s Strictly attracted 1 million more viewers than last week, making it Sunday’s most-watched programme.

An average 9.4 million tuned in to watch fashion designer Julien Macdonald get sent home following his dance off with Countdown’s Rachel Riley.