The R&B singer has now claimed five UK number one singles since he first reached the top spot in 2006 with 'So Sick'.
The Stargate-produced track - which was co-written by Sia - had battled with new singles from The Script and Pink all week, but eventually came out on top.
The Script equal their highest ever chart placement by entering at number two with their will.i.am collaboration 'Hall of Fame'.
Pink's 'Blow Me (One Last Kiss)' completed a top three of new entries by landing in third position.
Little Mix drop three from last week's number one to four with 'Wings', while previous chart-topper 'Bom Bom' by Sam and the Womp slips to five.
Owl City and Carly Rae Jepsen drop one place to six with 'Good Time', and Public Enemy slip three to seven with 'Harder Than You Think'.
Taylor Swift is a non-mover at eight with 'We Are Never Ever Getting Back Together', while Rita Ora drops six to nine with 'How We Do (Party)'. Fun. climb up four spots with 'Some Nights' to complete the Top 10.
Flo Rida's latest single 'I Cry' lands at 11 after being released midweek. Cheryl Cole leaps up nine places to 15 with new single 'Under the Sun', while Plan B enters at 27 with 'Deepest Shame'.
Professor Green's new track 'Avalon' is a new entry at 36, with The Vaccines landing at 39 with 'Teenage Icon'.
Watch the video for Ne-Yo's 'Let Me Love You' below:
Source: Official Charts Company
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