The track - featuring Janelle Monáe - finally topped the singles chart after seven weeks inside the top 40. It has now sold 431,000 copies to date.
The Wanted land at number two with 'Chasing the Sun', narrowly losing out by just over 3,000 copies after they led the pack earlier in the week.
Carly Rae Jepsen's 'Call Me Maybe' is a non-mover at three after nine weeks around, while Rita Ora slips three from last week's number one to four with 'R.I.P'. Alex Clare falls one to five with 'Too Close'.
Paloma Faith's new single 'Picking Up the Pieces' enters at seven ahead of new album Fall To Grace, which is released tomorrow.
Jennifer Lopez lands at 11 with 'Dance Again', a collaboration with Pitbull, while the rapper's Men in Black III theme 'Back in Time' also enters at 23.
Kylie Minogue manages to enter the chart at 31 with 'Timebomb', just two days after its digital release.
Martin Solveig also achieves a new entry at 36 with new single 'Night Out'.
Gavin DeGraw re-enters the top 40 for the first time since 2004, with his One Tree Hill theme 'I Don't Want to Be'. Jay-Z and Kanye West also climb back to 34 with 'Paris' following their London gigs.
The Saturdays drop ten spots to 17 with '30 Days', while Professor Green climbs up nine places to 18 with 'Remedy'.
Coldplay's duet with Rihanna 'Princess of China' also rises ten places to 20.
Watch the video for fun.'s 'We Are Young' below:
Source: Official Charts Company
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