Valmiki Ramayana Yuddha Kanda Sarga 70 Shloka 15

महाबलः mighty, वालिपुत्रः Vali's son, संयुगे in battle, अस्य his, विषाणम् tusk, निष्कृष्य removed, देवान्तकम् Devanthaka, अभिद्रुत्य jumping over, ताडयामास hit him.

Mighty son of Vali removed the tusk of the elephant and hit Devanthaka with it by jumping over him in the battlefield.