1 Samuel 17:49-51

Complete Jewish Bible

⁴⁹ David put his hand in his bag, took out a stone, and hurled it with his sling. It struck the P’lishti in his forehead and buried itself in his forehead, so that he fell face down on the ground. ⁵⁰ Thus David defeated the P’lishti with a sling and a stone, striking the P’lishti and killing him; but David had no sword in his hand. ⁵¹ Then David ran and stood over the P’lishti, took his sword, drew it out of its sheath, and finished killing him, cutting off his head with it.

When the P’lishtim saw that their hero was dead, they fled.