Valmiki Ramayana Yuddha Kanda Sarga 78 Shloka 17

अथ and there, तदा then, तस्य his, सारथेःcharioteer, करात् hand, प्रतोदःlong whip, प्रभ्रष्टःdropped down, तस्यरक्षसः that Rakshasa, ध्वजः standard, सहसाsuddenly, दैवात् by divine will, पपात fallen

There, the long whip dropped from the charioteer's hand and the Rakshasa's standard had fallen suddenly by divine will.