Iran will meet pre-tournament favorites Japan in the Asian Cup quarter-finals after surviving extra time with 10 men before defeating Syria 5-3 on penalties on Wednesday.
Japan beat Bahrain 3-1 despite another mistake from goalkeeper Zion Suzuki, as Brighton winger Kaoru Mitoma made his first appearance in Qatar after injury.
Skipper Ehsan Hajsafi scored the winning penalty for Iran, who are ranked 70 places above Syria and were comfortably the better team for much of the game.
Iran played the last 30 minutes with 10 men after Porto striker Mehdi Taremi was sent off for a second yellow card with the game 1-1 at the end of normal time.
Goalkeeper Alireza Beiranvand was the penalty hero for Iran, saving Syria's second spot-kick from Fahd Youssef.
Iran coach Amir Ghalenoei said he was "not happy with two or three" of his players, without saying who.
"We could have scored five goals up until the 70th minute," he said, AFP reported.
Along with holders Qatar, Iran came into the game as the only team left in the competition with a 100 percent record. They are pursuing a first Asian Cup crown since 1976.
Taremi was a central figure, winning a first-half penalty and putting it away to give Iran a deserved lead.
Syria had barely been in the game but equalized just after the hour, also from the spot, before Taremi was sent off in second-half injury time.
The two teams could not be divided in extra time, even with Iran playing with a man fewer.
Iran will meet Japan on Saturday.
Syria's wily Argentine Hector Cuper praised his players' "sacrifice", adding: "I can't ask more of them."
The 68-year-old refused to commit his future to Syria, saying: "Next week we will sit together (with football officials) and talk and see if I will stay or I have other options."
Captain Wataru Endo warned that Japan's rivals will "exploit" their weaknesses after they wobbled before defeating Bahrain to book their place in the last eight.
Japan looked to be cruising after goals either side of half-time from Ritsu Doan and Takefusa Kubo, but an own goal from error-prone goalkeeper Suzuki let Bahrain back in the game.
Ayase Ueda restored Japan's cushion with his fourth goal of the tournament, but Liverpool midfielder Endo warned that their quarter-final opponents might not be so forgiving.
"In football, teams are analyzing you and trying to find out where there are gaps that they can exploit," he said.
"Teams have looked at us at the tournament so far and it's not easy to defend against.
"It's important that we don't let our concentration drop for the full 90 minutes."
Mitoma came off the bench for Japan in the second half to play his first game since injuring his ankle on December 21.
The quarter-finals begin on Friday when surprise-package Tajikistan, the lowest-ranked team left at the tournament, face Jordan.
Australia play Son Heung-min's South Korea later the same day.
In the fourth quarter-final, Qatar play Uzbekistan, on Saturday.
