Teenage singer-songwriter Lorde has stormed to the top of the charts with her debut single Royals.
The 16-year-old from New Zealand held off competition from X Factor star James Arthur to claim her first UK number one.
James had to settle for the runner-up slot with You're Nobody 'Til Somebody Loves You, his first release since his X Factor winner's single Impossible spent two weeks at Number One over Christmas and New Year.
Counting Stars, last week's chart-topper from OneRepublic, fell to third place after two non-consecutive weeks in the driving seat.
Katy Perry climbed back up two places to fourth with Roar, which spent two weeks at the top last month.
Dutch brothers Sjoerd and Wouter Janssen - better known as Showtek - came in at five with Booyah, which features DJs We Are Loud! and vocalist Sonny Wilson.
Katy topped the album chart with Prism, outselling James Blunt's Moon Landing, by almost 12,000 copies. Prism is the second album by the Californian to hit number one. Her last album Teenage Dream spent a week there in 2010.
Tribute, last week's chart-topping album from John Newman, slipped two places as the Arctic Monkeys climbed back up two places to fourth with their latest release AM.
Italian opera star Andrea Bocelli claimed his eighth top ten album with Love In Portofino, new at number five.