The track, which the singer performed on last week's X Factor results show, will be her fourth UK No.1 if she holds on until Sunday's official announcement.
Elsewhere in the top ten, Alexis Jordan debuts at number three with 'Happiness', while Shakespears Sister re-enter the chart at number nine with 'Stay', following Cher Lloyd's live rendition of the song on Saturday's X Factor.
Further down the chart, will.i.am and Nicki Minaj's 'Check It Out' currently stands at number 12, and Ne-Yo lands at 20 with 'One In A Million'.
Tinchy Stryder and Taio Cruz's 'Second Chance' is at 21, Roll Deep and Alesha Dixon's 'Take Control' debuts at 26 and Jamiroquai's 'White Knuckle Ride' stands at 34.
On the album chart, Cheryl Cole's sophomore effort Messy Little Raindrops is fending off competition from Bon Jovi's Greatest Hits: they currently stand in positions one and two respectively.
Rumer's debut record Seasons Of My Soul enters at number 3, while Jamiroquai's 'Rock Dust Light Star' lands at five.
Neil Diamond's Dreams follows behind at number eight, and Ne-Yo's fourth studio album, Libra Scale is at number nine.
Their official chart positions will be announced this Sunday between 4pm and 7pm.
SourceOfficial Charts Company