After the death of 'Hazer Mard', the Muslim army advanced for a general attack. The two armies met with a clash of steel, and the battle raged with unabated fury. The Muslims struck at the heavily armed Persians, but the Persians stood their ground, and repulsed all attacks. Then Andarzaghar ordered a counter attack. The Muslims were able to hold the attack for some time, but as the Persians intensified their pressure, the Muslims began to lose ground and fell back. Andarzaghar exhorted his men to step up their pressure for victory was very much in sight.

At that critical juncture, Khalid gave a signal. The next moment over the crest of the ridge that stretched behind the Persian army appeared columns of mounted Muslim warriors. Raising shouts of 'Allah-o-Akbar', the Muslim cavalry charged at a gallop, and the plain of Walaja shook under the thundering hooves of the Arab horse.

The Persians who were pressing forward were now caught in a trap. When they turned their face to meet the charge of the Muslim cavalry, the main Muslim army delivered a furious charge. The ring of steel became tighter round the Persians and in whatever direction they turned they were struck down by sword and dagger.

The battlefield of Walaja became a slaughterhouse for the Persians. The very helplessness of the Persians excited the Muslims to greater violence. The bulk of the Persian army was annihilated. Andarzaghar fled from the battlefield and penetrated deep into the desert where he lost his way and died of thirst. The battle of Walaja ended in a victory for the Muslims. That was the third consecutive victory of the Muslims over the Persians.

Consequences of the battle of Walaja. The victory of Walaja established the superiority of the Muslim fighting forces. Once again a large booty fell into the hands of the Muslims. Four-fifth of the spoils were distributed among the Muslim warriors on the spot, and the remaining one-fifth were sent to Madina. As the news of the Muslim victory reached Madina, Abu Bakr offered special prayers of thanksgiving to Allah.