Manchester United's Park Ji-Sung helped Korea Republic to a share of the spoils in their South Africa 2010 qualifier at a rain-soaked Azadi Stadium.
Javad Nekounam, who plays for Spanish side Osasuna, sent more than 80,000 home fans wild when he fired home a close range free kick for Iran on the hour mark.
But Park pounced with a decisive header 21 minutes later when Iranian goalkeepr Mehdi Rahmati managed to only punch out an incoming free kick, giving the 300 South Korean expatriates in the arena a late reason to celebrate.
The result leaves Korea Republic top of Group 2 with eight points, trailed by their northern neighbour Korea DPR with seven points, followed by Iran with six points. Saudi Arabia are fourth on four points with the United Arab Emirates on one point. All team have played four matches so far.
Despite the rain that had drenched the city since early morning, home fans had been hoping for a win that would boost Iran's qualifying hopes in the wake of two previous lacklustre performances.
Iran drew 1-1 with the United Arab Emirates in November and shared the spoils against Thailand leaving their coach, Ali Daei, under intense pressure.