Katy Perry currently has a sizeable lead over Lady Gaga in the US singles chart.

Both acts released highly anticipated comeback singles earlier this week and they are facing off in a fierce chart battle.

Perry's 'Roar', however, looks set to beat Gaga's 'Applause' when the final chart placings are revealed next week.

Billboard reports that 'Roar' is expected to shift 450,000 downloads in its first week, whilst 'Applause' is due to hit around 200,000 to 225,000.

Whilst Perry's single was released a day earlier than Gaga's, the lead is a hefty figure and is set to see the 'Part of Me' star hit No.1.