Valmiki Ramayana Yuddha Kanda Sarga 79 Shloka 39

तदा then, काकुत्थ्सेन by Kakuthsa, तेन by that, अस्त्रण missile, हतम् killed, रक्षः raksha, सञ्चिन्नहृदयं heart split open, तत्र there, रणए in the battlefield, पपात fell down, ममार च dead

Then struck in the battlefield by that missile of Kakuthsa, the Rakshasa fell down with his heart split open and died.