The last important battle in the Ramayana was between Bhagavan Sri Ram and demon king Ravana. This was an all-important encounter. It was not easy to kill Ravan as he had powerful defense and magical powers. So how did Ram kill Ravana?
In the final battle both Ram and Ravana used several divine arrows against each other. All the arrows were nullified by them. Finally, Sri Ram shot arrows and knocked off each of Ravana’s ten heads. But to the amazement of all standing in the battlefield, new head grew immediately. Each time a head appeared Ravana grew more powerful.
Finally, Sri Ram fired the Brahmastra, which was imparted to him by sage Agastya. Sage Agastya had imparted this powerful arrow to Sri Ram while he resided in the Dandaka forest with his wife Mata Sita and brother, Lakshman.
The Brahmastra pierced through chest of Ravana. He fell down chanting the name of Bhagavan Sri Ram.