X Factor winner beats Robbie to the top of British charts
Both acts kicked off their chart campaigns with appearances on The X Factor last weekend.
It emerged in midweek that Burke’s track, which features US rap superstar Flo Rida, was selling about double that of Williams.
She said: “I’m blown away by the success of the single. I’ve been recording my album for the last six months, so I’m hugely excited to finally be sharing my music with everyone.”