Lionel Messi curled a stunning 91st-minute winner to send Argentina through to the World Cup knockout stage and rob the excellent Iran of a deserved point.
Iran spent much of the first half under pressure but more than once threatened to inflict what would have been a huge upset.
Argentina’s celebrations at the final whistle were wild and prolonged, while the sight of coach Alejandro Sabella embracing Messi at the tunnel gave an indication of what this meant to the two-time champions.
The build-up was dominated by talk of a rift between Messi and Sabella, the captain having expressed his displeasure at the 5-3-2 formation used in the first half against Bosnia-Hercegovina when Messi also scored the decisive goal.
Sabella duly reverted to the Barcelona forward’s preferred 4-3-3 and was rewarded by his star man at the last