שמואל א, פרק י״ז, פסוק נ״א

The climax of the battle arrives when the giant falls, and the young challenger moves in to secure the victory. Having launched the stone from a distance, David runs forward and stands directly over the fallen Philistine [מצודת דוד, רד״ק, ביאור שטיינזלץ]. He takes the giant's own sword and pulls it from its sheath [מצודת ציון, מצודת דוד, ביאור שטיינזלץ]. Freeing the blade is an act of bravery and skill in its own right; the weapon was tightly locked shut, and only the Philistine's attendant, Uriah, knew how to open it [חומת אנך].

The exact moment the giant dies is a matter of discussion. Some explain that the sling stone killed him earlier, and David only uses the sword to cut off his head [רד״ק, מצודת דוד]. Others point out that the stone merely brought him down, and David actually stabs him to death with the sword before beheading him [מלבי״ם, ביאור שטיינזלץ].

Seeing their champion defeated, the Philistines flee. This mass escape breaks the original condition of the battle, which stated that the losing side would surrender and become slaves. An overwhelming terror grips the Philistines as they watch the fate of their hero, causing them to panic and run [ביאור שטיינזלץ]. Additionally, because the fight did not unfold like a standard, official duel, the original rules are considered canceled. As a result, the Philistines choose to run away, leaving the Israelites to chase after them [מלבי״ם].