Valmiki Ramayana Yuddha Kanda Sarga 70 Shloka 65

स्वया his own, गदया mace, भग्नः shattered by, सः he, मत्तः Matta विशीर्णदशनेक्षणः whose eyes had been crushed, तदा then, वज्राहतः struck by lightning, अचलःइव like a mountain, निपपात fallen.

Shattered by his own mace, Matta (Mahaparsva), whose eyes had been crushed, had fallen like a mountain struck by lightning.