South Korea were held to a frustrating scoreless draw by 10-man Iran in Seoul Thursday when a win would have seen the home side qualify for next year�s World Cup.

Already qualified, Iran played the majority of the second half in front of a capacity crowd at the Seoul World Cup Stadium a man down after Saeid Ezatolahi�s red card but extended their undefeated record in Asia�s Group A to nine matches.

With China upsetting Uzbekistan 1-0 at home, South Korea could not breach Iran�s defense to clinch their ninth consecutive World Cup finals berth in front of more than 63,000 fans.

South Korea have a two-point lead over third-placed Uzbekistan in Group A, and will need to avoid defeat against the Uzbeks in Tashkent on Tuesday to book their ticket on the plane to Russia.

South Korea and Iran traded few chances in the opening half. 

Tottenham Hotspur�s Son Heung-Min took a free-kick from just outside the box in the 17th minute, but his low shot rolled off the leg of an Iranian player and out of play.

Midfielder Jang Hyun-Soo almost headed one in for the hosts two minutes later, but saw his attempt bounce just wide of the gaping Iranian net.

Iran’s Ehsan Hajsafi (R) fights for the ball in front of a sold-out crowd in Seoul, Aug. 31, 2017.

Iran recorded just one attempt on target before half-time in the 37th minute when Heerenveen forward Reza Ghoochannejhad managed to get off a shot with three defenders smothering him, though it went straight to goalkeeper, Kim Seung-Gyu.

Iran were reduced to 10 men seven minutes into the second half, when Saeid Ezatolahi was shown a straight red card after he recklessly stamped on the head of Kim Min-Jae following an aerial clash between the pair.

South Korea couldn�t take advantage of their extra man and wasted another free-kick opportunity in the 78th minute, when Kwon Chang-Hoon�s left-footed shot from outside the right edge of the box sailed over the bar.