Sci-fi thriller Lucy is spending a second week at the top of the U.K. box office chart after raking in $3.2 million (£1.9 million) in takings over the weekend (29-31Aug14).
The action movie, starring Scarlett Johansson as a woman with supernatural abilities, held off competition from its nearest rival, new comedy Let's Be Cops, which took $2.7 million (£1.6 million) in its opening three days.
Hit comedy sequel The Inbetweeners 2 dropped one place to third, with weekend ticket sales of $2.2 million (£1.3 million), and Sin City: A Dame To Kill For was a new chart entry at four, with $1.8 million (£1.07 million).
The top five was rounded out by summer blockbuster Guardians of the Galaxy, which took $1.7 million (£1.02 million).
Perry appeared on James Corden's 'The Late Late Show' on Monday and addressed her long-standing rivalry with Swift.