1 Samuel 17:49-51

New Revised Standard Version Catholic Edition

⁴⁹ David put his hand in his bag, took out a stone, slung it, and struck the Philistine on his forehead; the stone sank into his forehead, and he fell face down on the ground.

⁵⁰ So David prevailed over the Philistine with a sling and a stone, striking down the Philistine and killing him; there was no sword in David’s hand. ⁵¹ Then David ran and stood over the Philistine; he grasped his sword, drew it out of its sheath, and killed him; then he cut off his head with it.

When the Philistines saw that their champion was dead, they fled.