Sam’s strength came from the anger he had acquired from being so utterly betrayed by  treacherous Gollum. He did not know what strength he had or if he could match that dreadful beast, he used all his strength to take out her eye, then when she tried to smother him, he was already ready with a knife striking at her age-old hide.

The lights almost went out but saving Frodo took precedence and kept him going at that dark hour.

He almost swooned at the stench of her blood. All lights had gone out; his only thought, free Mr. Frodo.

A/N- For the tolkien100 challenge "Lights Out"