KE$HA is on course to become only the 17th act to debut at number one on the U.S. pop charts.
The singer's We R Who We R is expected to rocket to the top of the Billboard Hot 100 when the chart is officially released on Thursday (04Nov10).
The party anthem has sold 280,000 downloads in its opening week.
We R Who We R will be the second track to debut at the top of the charts this year (10) - Eminem's Not Afraid shot straight to number one in May (10).
Perry appeared on James Corden's 'The Late Late Show' on Monday and addressed her long-standing rivalry with Swift.