The singer's new track 'Troublemaker' leads the singles tally, holding off competition from Girls Aloud's 'Something New' at number two.
Meanwhile, Alicia Keys's 'Girl On Fire' zooms to number eight following her performance on The X Factor results show last night (November 18) and Rudimental's 'Not Giving In' is at 13.
On the album chart, Rihanna's Unapologetic has taken an early lead, followed by the latest Now That's What I Call Music compilation at two.
Example's The Evolution of Man currently sits at three, Little Mix's DNA is at seven, and Coldplay's Live 2012 album bows at ten.
The first official midweek chart is announced on Wednesday at 4.30pm.
Watch Olly Murs's 'Troublemaker' video below: