Three-times winners Iran, who had already won the group and will play South Korea in the last eight, made nine changes to their team but still beat United Arab Emirates 3-0.
Iran finished Group D with nine points from three matches with Iraq second on six. North Korea and UAE exited the tournament with one point apiece having failed to score a goal.
The quarter-final against Australia, the best FIFA ranked side in the tournament, will bring Iraq's German coach Wolfgang Sidka up against his compatriot Holger Osieck.
"I know him very well," Sidka told reporters. "Unfortunately two German coaches play each other in the quarter-finals, I would like to see him later on."
German-based striker Jong Tae-se had the Koreans' best chance with 13 minutes left but his low shot on the turn was straight at the goalkeeper.
"I think we deserved this victory especially in the first half I was very satisfied how we played," Sidka said.
"We got good experience during the tournament so we understand defending is important but attack is more important so in the future we will try and make our games more attacking," Jo, who was non-committal about his future, said.
Afshin's joy was short-lived, however, as he was red-carded five minutes later for fouling the goalkeeper.
There was still time for UAE defender Khalid Sebil to be sent off and Mohammad Nori added a second when he swept a shot into the corner of the net. UAE's Walid Abbas capped a disappointing tournament for his side by scoring his second own goal of the tournament in stoppage-time.
"I'm happy to go to the second stage with a perfect record and to be the only team with nine points," Iran coach Afshin Ghotbi said.
"Having said that, all teams start fresh and it's like a new tournament."
