Iran failed to attempt a single shot on target in this match - the first time that they have failed to do so in a World Cup game (14 games overall). The kickoff of the second half, however, saw the Spanish side pick of momentum in their chase for a goal, creating a couple of chances.
After a stale first 45 minutes, which Spain dominated but rarely threatened, Diego Costa broke the deadlock less than 10 minutes into the second half, albeit with a huge slice of good fortune. The Iranians thought they had scored an equaliser, but Saeid Ezatolahi's header was disallowed for offside after the referee consulted the Video Assistant Referee.
Iran did not concede a single goal until the last of their 10 final round Asian qualifiers when their spot in Russian Federation was already secure, at the same time creating enough going forward to win six of those matches.
Federation Internationale de Football Association statistics showed that Spain made 17 attempts at the goal throughout the match, while Iran made only five.
Spain will end their Group B campaign against eliminated Morocco on Monday, while Iran face Portugal, where only a win would be enough to secure them a place in the round of 16. Do not cut, copy or lift any content from this website without our consent.
"What we did in our last match (beating Morocco) is not important but neither is Spain's reputation.
We are very happy with three points".
Costa, who also scored two goals in the opening match, has three goals at this year's World Cup, trailing Cristiano Ronaldo by one. On one occasion, in the 39th minute, Diego Costa objected after Iran goalkeeper Alireza Beiranvand began jumping in pain, insisting to the referee that Costa had stamped on his foot.
"We are well aware of Spain's reputation, so we'll have to play our best game ever".
"The Iranian team are very strong, both in defending and attacking".
But Hierro, like Iniesta, has no intention of being the man who steered Spain to an unthinkable World Cup disaster. "We're a team and we have to stick together".
Iran coach Carlos Queiroz has denied his players faked getting hurt during their defeat to Spain on Wednesday and seemingly criticised the conduct of Sergio Ramos for his Champions League final tussle that injured Mohamed Salah.
While it remains to be seen if he will start or not, Hierro will surely feel tempted to select him following a shaky display from Nacho Fernandez at right-back against Portugal.