The battle for Sarne was the first time the Sarnori fought with a unified army, after finally realizing the gravity of the situation.
The Sarnori had a numerical and material advantage, and their scythed chariots made short work with the Dothraki horses. After Khal Haro was killed, the Dothraki fell back, feigning defeat in order to trick the Sarnori into pursuing them. The Dothraki archers subsequently showered the Sarnori with arrows. Two khalasars hit the Sarnori flanks while a third hit them from behind. The Sarnori force was wiped out, and King Mazor Alexi was killed.
Having destroyed the Kingdom of Sarnor, the Dothraki now enjoyed almost complete superiority in the Dothraki Sea. This would persist until the disastrous Battle of Qohor, which finally spelled an end to the idea of Dothraki invincibility.