Pixie Lott has scored her second number one single with Boys and Girls, three months after her debut release, Mama Do, hit the top spot.
The 18-year-old's success knocked Jay-Z's track with Rihanna and Kanye West, Run This Town, down to number three.
Dance DJ David Guetta and Akon climbed one place to number two, while Mika was a new entry at four with We Are Golden.
In the album chart, Dame Vera Lynn became the oldest living artist to have a number one hit - aged 92!
Dame Vera Lynn
The singer, who became famous around 70 years ago for her Second World War hit We'll Met Again, knocked the Arctic Monkeys off the top spot.
When she found out she said: "I am extremely surprised and delighted, and a big 'thank you' to all my fans for putting me there."