The track sold 108,000 copies following a performance on last week's X Factor results show, to knock Calvin Harris and Florence Welch off the top spot.
It is Labrinth's first UK number one single as a lead artist following his 'Pass Out' collaboration with Tinie Tempah in 2010, while Sandé previously topped the chart with Professor Green on 'Read All About It'.
Swedish House Mafia sell a further 86,000 to stay at number two with 'Don't You Worry Child', while Harris and Welch drop to places to three with 'Sweet Nothing'.
Rihanna is a non-mover at four with former number one 'Diamonds', while fellow chart-topper Psy drops two to five with 'Gangnam Style' at five.
JLS just miss out on a top five placing with 'Hottest Girl in the World', which lands at six.
Adele drops two places with her Skyfall theme to seven, while Maroon 5 are a non-mover at eight with 'One More Night'. Taylor Swift also falls two to nine with 'We Are Never Ever Getting Back Together'.
Emeli Sandé scores a second Top 20 placing this week, after her Naughty Boy collaboration 'Wonder' lands at ten.
Disclosure climb a further five places to 12 with 'Latch', while Bastille achieve their highest chart placement yet, with new single 'Flaws' entering at 21. The Lumineers also score a new entry at 22 with 'Ho Hey'.
Watch the video for Labrinth's 'Beneath Your Beautiful' below:
Source: Official Charts Company
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