Zob Ahan left it late to snatch a 3-2 victory over Group A rivals Al Nassr in the AFC Champions League on Monday.
The Iranian side were behind inside five minutes in Dubai but goals from Mohammad Nejad Mehdi and Vahid Mohammadzadeh put them ahead at the break.
A penalty from Abdelrazaq Hamdalla looked to have earned Al Nassr a point, but Amir Motahari ensured the visitors left with the win in stoppage time.
Victory sees Zob Ahan move onto four points from their two matches, leaving them level with Al-Zawraa, who thrashed Al Wasl 5-0 in Karbala.
All four teams in Group B have one win to their name after the second round of games, Al Wahda and Al Rayyan both getting off the mark with victories.
Goals from Lucca Borges and Gelmin Rivas saw Al Rayyan come from a goal down to beat Lokomotiv Tashkent 2-1, while Al Wahda eased to a 4-1 triumph over Al Ittihad.
Leonardo netted twice for Al Wahda as they bounced back from their opening game defeat to Lokomotiv last week.