The delicate darling Katrina Kaif took everyone by surprise by displaying her tough side while shooting for an action sequence in her forthcoming venture Ajab Prem Ki Ghazab Kahani.

If sources are to be believed Katrina and Ranbir were required to climb a ladder which was at a height of 200 feet while Ranbir was to save Katrina from goons and then escape on a jet ski.

The source goes on to add, "Everyone on sets was quite skeptical about Katrina. However, Katrina amazed everyone as she comfortably climbed the ladder leaving Ranbir lagging behind."

Ever since that day Ranbir has always addressed Katrina as Rambo's sister Sambo.