There Qahtaba sent him north to Shahrazur to counter an Umayyad army under Uthman ibn Sufyan threatening his right flank. Abu Awn joined forces with another Abbasid force under Amir ibn Isma'il, and a local tribal chieftain, but his forces, some 4,000 men, remained inferior to the Umayyad army. Nevertheless, he decided to attack, and on 10 August 749, his army routed the forces of Uthman (who according to some accounts fell in the battle) and captured the district of Shahrazur.[6][7]