South African Ayanda Patosi scored Foolad’s goal in the 39th minute.
As the clock ticked, Ahal could not find a response and its misery was compounded when a frustrated Selim Nurmuradov was shown a straight red in injury time for elbowing Sina Shahabbasi as Foolad held on to its lead to claim the second victory in the campaign.
The UAE’s Shabab Al-Ahli also defeated Al-Gharafa 8-2 in the same group.
Foolad is scheduled to play Al-Gharafa on Friday and will advance to the next stage if it beats the Qatari team.