Story of Narasimha avatar of Vishnu and Demon Ambarya is
mentioned in the Brahma Purana. This story happens after Narasimha vanquished
Hiranyakashipu.
Legend has it that after killing Hiranyakashipu, Narasimha roamed
around the world annihilating all that practiced Adharma. He killed scores of
demons.
He then arrived on the banks of Godavari River near
Dandakaranya forest.
Demon Ambarya ruled the region. Even Devas were unable to
defeat him.
Demon Ambarya and his large army attacked Narasimha. In the
terrible fight, the entire army was vanquished. The invincible demon was killed
and the place was rid of his terror.
The place where the demon was vanquished came to be
known as Narasimha tirtha