The Christian contingent began their retreat on 24 December 1443, after the Battle of Zlatica. The Ottoman forces followed them across the rivers Iskar and Nišava and in the Kunorica pass attacked (some sources say ambushed by) the rear flanks of the retreating armies composed of armies of the Serbian Despotate under command of Đurađ Branković. The battle took place during the night, under the full moon. Hunyadi and Władysław who were already through the pass left their supplies guarded by infantry and attacked Ottoman forces near the river on the eastern side of the mountain. The Ottomans were defeated and many Ottoman commanders, including Mahmud Çelebi of Çandarlı family (in some earlier sources referred to as Karambeg), were captured.

The Ottoman defeat in the Battle of Kunovica and capture of Mahmud Bey, the Sultan's son-in-law, created the impression of an overall victorious campaign. According to some sources, Skanderbeg participated in this battle on the Ottoman side and deserted Ottoman forces during the conflict.