Suwon Bluewings paid the price for missing several chances as the South Korean team was held 1-1 at home by Zob Ahan in Wednesday's first leg of the Asian Champions League quarterfinals.
In a tight game, Zob Ahan took the lead through Mohammad Ghazi after 56 minutes but 10 minutes later, Park Hyun-beom volleyed in the equalizer for Suwon.
The result gave the Iranian club - last year's runner-up in this competition - an advantage as it will host the second leg on Sept. 28.
Suwon was on top for most of the 90 minutes and started strongly with Macedonian striker Stevica Ristic coming close on a number of occasions.
Zob Ahan was content to sit back and try to get an away goal on the counterattack and that is precisely what happened 10 minutes into the second half.
Igor Castro got behind the Suwon defense and set up Mohammad Ghazi to score from close range.
Suwon's impressive record of not having lost in 26 straight home games in continental competition was in jeopardy until Park Hyun-beom volleyed in an equalizer 10 minutes later.
The Bluewings continued to push forward in a bid to take a lead to Iran for the second leg but both Yeom Ki-hun and Park missed opportunities.
The eventual winner will play either Iran's Sepahan or Qatar's Al-Sadd in the semifinal, and the competition winners will claim a berth in the Club World Cup.
