Chimba scored the only goal of the match from the penalty spot in the 44th minute at King Fahd International Stadium on Saturday.
The win sends the Iranian side into second in the group behind Saudi Arabia’s Al-Nassr, who they will face on Tuesday, while Al-Wehdat remains without a goal after two matches in its first ACL campaign.
With a point each going into the match, the opportunity existed for one of the sides to put its stamp on a group which had remained all square on Matchday One, and it was Foolad who comprehensively seized it.