The blues faced Qatari opponents in Tehran's Azadi Gym and stood in the first place of Group A of the AFC Champions League.
Esteqlal had already disappointed fans following a goalless home draw with the UAE's Al-Jazira in the AFC Champions League.
The Blues were far from the excellent form which gave them a 2-1 away victory over Al-Ahli two weeks ago.
Esteqlal manager Samad Marfavi said the tight schedule of Iran's Premier League, the Hazfi Cup and the AFC Champions League had exhausted the players and resulted in their lack of concentration during the match.
Marfavi was criticized for bringing Esteqlal's top scorer Arash Borhani only in the last few minutes of the match.
However, he defended his decision, saying Borhani had just recovered from an injury and could not play from the beginning.
Later on Tuesday, Qatar's Al-Gharafa beat Saudi Arabia's Al Ahli to stand in Group A first place with six points out of two matches. Esteqlal is second with four points.