Vishnupurana 5.7.45

5.7.45

vraṇāḥ phaṇe 'bhavaṃś cāsya kṛṣṇasyāṅghrinikuṭṭanaiḥ
yatronnatiṃ ca kurute nanāmāsya tataḥ śiraḥ //

Being thus reminded of his real character by Rāma, Krishna smiled gently and immediately freed himself from the coils of the snakes. And catching with both his hands the middle hood of the serpent-king, that highly powerful (Krishna) bent it down and set his foot upon the hitherto-unbended hood; and danced upon it victoriously. And the hood of the serpent was bruised by the treading of Krishna's feet, and wherever the snake attempted to raise his head, it was again trodden down. Trampled upon by the feet of Krishna as they changed position in the dance, the snakes fainted and vomitted froth much blood. Seeing the head and neck of their king thus bruised and blood flowing from this mouth, the females of the snake-king implored the mercy of the Slayer of Madhu.