Jose Marigo Igor put the visitors ahead after 12 minutes before Seyed Mohammad Hosseini completed the scoring three minutes before the break.
The win was Zob Ahan's third in four games and means they top the standings with 10 points, one ahead of Sanat Naft.
Pas Hamedan climbed up to third with Hamid Kazemi's first-half goal sealing a 1-0 win over Teraktor Sazi.
Elsewhere, Mojtaba Jabari's late strike rescued a point for Esteghlal at home to Steel Azin.
Mohammad Gholami's second goal of the game had given Steel Azin a 2-1 lead with four minutes remaining but Jabari struck in stoppage time to earn a share of the spoils.
Finally, Sepahan edged Shahin 1-0 while Peykan drew 1-1 with Malavan.