Last year’s runners-up recorded their fourth win in five group games, while Emirates’ chances of advancing to the next round suffered a severe blow.
Emirates, second behind Zob Ahan and looking to make it a third consecutive win at home, were without star striker Nabil Daoudi while key defenders Hadef Saif Al Zaabi and Mustafa Al Saedi sat out due to suspension.
The Iranian side started brightly and in the second minute Mohammad Khalatbari pulled wide but then shot straight at Ahmed Al Zaabi in the Emirates goal.
The hosts had their first chance when Jordanian Amer Deeb was fouled by Farshid Kouhi and from the resulting free-kick, Karim Kerkar saw his effort just miss the mark.
The Zob Ahan forwards displayed a lot of pace but Emirates managed to stave off the attacks. In the 15th minute, Zob Ahan defender Seyyed Farimani advanced into the Emirates half but his powerful shot was saved by Al Zaabi.
Though Zob Ahan saw more of the ball, the UAE second division side did not bow down and four minutes later Deeb crossed into the box but before Hadj Bougueche could reach for a header, Shahab Gordan plucked the ball out of the air.
Zob Ahan again came close as Ghasem Hadadifar set off on a fine run after snatching the ball from an Emirates forward before sending in a cross towards Ghazi that was intercepted by Al Zaabi.
The best move for Emirates came in the 32nd minute when Adnan Al Balooshi passed to Hareb Al Madhawi and he found Kerkar inside the box but the latter shot just wide.
Kerkar and Deeb had two more efforts before the break while at the other end, Igor Castro also missed a chance to leave the teams locked at 0-0 at half time.
Four minutes after the break Al Zaabi did very well to tip over a dipping shot from Hossein Mahini from well outside the box while in the 56th minute, Emirates had another escape as a powerful effort from Hadadifar flew just over the bar.
Adnan Al Balooshi, who impressed with his runs down the flank, wasted a great chance for Emirates in the 62nd minute by shooting wide when well placed, then only a minute later Mahdi Rajabzadeh’s free-kick was well saved by Al Zaabi.
The visitors looked more purposeful in the second-half while Emirates began to launch counter-attacks and Castro could have done better with a weak attempt following a goalmouth scramble in the 67th minute. Two minutes later Ghazi’s volley was saved by Al Zaabi
Emirates midfielder Abdulla Al Balooshi cleared an effort off the line in the 78th minute before Zob Ahan finally struck two minutes later. Castro slipped the ball to the right and Ghazi made no mistake, his left-footed effort beating the advancing Al Zaabi.
Emirates threw everyone into attack in the final minutes and Kerkar’s corner almost found its way into the net before it was headed away by a Zob Ahan defender.
Deeb's shot hit a defender while in stoppage time Kerkar’s free-kick again missed the mark as Zob Ahan held on for victory.