US pop star Katy Perry ensured the iTunes Festival came to a Roar-ing close, as she headlined on the final night.
The 28-year-old took to the stage at the Roundhouse in London to play tracks from her "darker" fourth album Prism, ahead of its release on October 21.
Wearing a sequinned leather bodysuit with a kilt, she opened with Walking On Air before performing hits California Gurls, Teenage Dream and I Kissed A Girl.
"Thank you London. Are you ready for some more Prism previews?" she told the screaming crowds.
"This is one of my favourite tunes," she added, introducing her new single Dark Horse.
Katy - born Katheryn Elizabeth Hudson - then swapped her kilt for a sheer skirt, as she cavorted with hunky dancers on Part Of Me.
"Right now we are going to get down and dirty, you know what I'm saying?" she said.
The singer, who is dating musician John Mayer following her divorce from funnyman Russell Brand, dedicated Firework to "anyone who has ever felt less," before ending her 45-minute-long set with Roar.
Katy is the latest act to headline the seventh year of the month-long festival, which Lady Gaga opened on September 1.
Sir Elton John, Arctic Monkeys, Justin Timberlake, Kings Of Leon, Tinie Tempah, Jessie J and John Legend were also part of this year's line-up.
:: Download the free official iTunes Festival app to watch the incredible performances on demand (available for a limited time). Visit:www.itunesfestival.com - follow: @itunesfestival #itunes festival