Milad Meidavoudi gave the capital's team the lead in the 9th minute in front of more than 10,000 spectators in the Azadi Stadium on Saturday.
After the first-half goal, Foulad was dominant and Reza Norouzi scored in the 63rd minute to equalize the match.
Five minutes later, Norouzi's double took the Khouzestan-based side three points from Tehran.
Esteqlal manager Parviz Mazloumi blamed his defenders for the home defeat, saying his team needed time to reach the ideal condition.
"I am not satisfied with my players' performance and the result," said Mazloumi.
Meanwhile, Foulad head coach Majid Jalali said that beating Esteqlal in the Azadi Stadium was not an easy job.
In other matches on Saturday, Steel Azin thrashed Pas 3-0 and Zob Ahan secured its second victory in a 2-1 win over its neighbor rival Mes.