 Under his command, the Zubayrid forces ousted the Azariqa from the Tigris river valley, forcing them to regroup at a place in Ahwaz called Sillabra, where he inflicted a decisive defeat against them in 685, in which 7,000 of their men were killed.The Azariqa consequently retreated east into Fars.Al-Muhallab remained in Ahwaz for a short period until Ibn al-Zubayr's brother, Mus'ab, became governor of Basra.