Alireza Jahanbakhsh's late header cancelled out Son Heung-min's opener as Iran drew 1-1 with South Korea in Tehran on Tuesday to remain on top of Group A in the final round of Asia's preliminaries for next year's World Cup.
The Feyenoord forward powered his effort past Kim Seung-gyu 14 minutes from time after Son had put the Koreans in front three minutes into the second half.
Dragan Skocic's side move onto 10 points from their first four games in Group A and remain two points ahead of the Koreans as the pair consolidated their hold on the top two positions in the standings.
Only the first two teams in each of the two groups in the continent's qualifying competition are guaranteed to progress to the finals while the third place finishers will advance to a series of playoffs.
Third-placed United Arab Emirates will take on Iraq later on Tuesday while Syria meet Lebanon.
Iran had won all three of their matches going into the clash at the Azadi Stadium and were unfortunate not to go into halftime with a lead.
Kim twice denied the home side in quick succession as Sardar Azmoun's low shot was parried to his left by the Kashiwa Reysol goalkeeper before another fine save - this time to his right - kept out Mehdi Taremi's overhead kick.
Those interventions were to prove crucial three minutes into the second half when Son netted with a trademark finish.
The Tottenham Hotspur forward was unstoppable as he latched onto a ball from inside the centre circle by Lee Jae-sung that evaded full back Sadegh Moharrami and Son coolly stroked the ball home.
Saeed Ezatolahi hit the post from distance as Iran pushed to maintain their early dominance in Group A and, with 14 minutes remaining, Skocic's side were level.
A determined Azmoun cut a lofted ball back from the bye-line and Alireza Jahanbakhsh powered his downward header beyond the outstretched arms of Kim.
Taremi then hit the post from distance with an unstoppable drive while substitute Na Sang-ho was denied a dramatic winner by Alireza Beiranvand deep into stoppage time.