In the match, held at the Al Shabab Stadium in Riyadh, Saudi Arabia, South Korea’s midfielder Bae Hyun-seo found the back of the net in the 19th minute but his goal was ruled out due to offside.
Iran could have broken the stalemate in the 35th minute but an unmarked Reza Ghandipour - with only keeper Hong Seong-min to beat - fumbled his close-range header.
The South Korea strike force seemed unable to get its game together, with an unguarded Kim Tae-won ballooning his shot from outside the area in the 66th minute.
At the other end, Ghandipour found space in the middle of the 18-yard box but his diving header to the right was way off target before Mohammad Khalifeh pulled off a superb save from Hong Seong-Min in the dying minutes to close out the match.
Korea, the 2020 champion, will face debutant Lebanon on Saturday while Iran play the 2018 winner Uzbekistan.