American pop star Bruno Mars has fired Rihanna from the top of the charts with new single Grenade.
It is the second number one for the singer-songwriter who was acclaimed for his debut hit, Just the Way You Are, last year. The song is also in the top 20, holding onto the number 17 slot.
His chart success comes in the week he was nominated for the International Breakthrough Act in the Brit Awards and saw his new tour, Doo-Wops and Hooligans, sell out in record time.
Jessie J, winner of the BBC's Sound of 2011, saw her first single Do It Like a Dude climb the charts to claim the number two spot with Rihanna settling for number three with What's My Name. The song features the rapper Drake.
Rihanna, however, can be consoled with holding onto the top of the album charts with Loud.
Katy B and Ms Dynamite's dance tune Lights On stayed at number four in the singles chart while X Factor winner Matt Cardle's previous number one When We Collide slipped down to number five.