Saudi Arabia's hopes of qualifying for a fifth straight World Cup received a major boost when Osama Al Harbi scored three minutes from time to give his side a come-from-behind win over Iran at Tehran's Azadi Stadium.
Masoud Shojaei had given the Iranians the lead in the 57th minute only for goals from Naif Hazizi and Al Harbi to earn the Saudis a win that moves them into third place in Group B of Asia's qualifying tournament for next year's World Cup finals.
The top two teams qualify automatically for South Africa with the third place team progressing to a play-off with their counterparts in Group A.
The victorious team from that clash then meets the winner of the Oceania qualifiers for a place in the finals.
Hazizi saw a first-half effort ruled out by Japanese referee Yuichi Nishimura while the Saudis also felt they had a legitimate penalty claim waved away when Nassir Al Shamrani was upended in the box by Iran goalkeeper Seyed Rahmati.
Iran, for their part, saw Saudi goalkeeper Waleed Abdullah brilliantly deny Mehdi Madhavikia with a fine stop when the Bundesliga-based midfielder was clean through on goal in the 27th minute.
Iran, however, looked set for all three points when Osasuna midfielder Shojaei struck a fine effort from the edge of the area that moved away from Abdullah and into the far corner of the goal.
But, with time running out and the Saudis becoming increasingly desperate, the impressive Hazizi struck back, sidefooting the ball home after a perfectly weighted through ball by Saleh Bashar.
With both teams needing a win to enhance their World Cup hopes, the Saudis took all three points back to Riyadh thanks to Al Harbi's late intervention, the central defender rising to glance Abdoh Autef's corner across Rahmati and into the far corner of the net.