It was about as visceral a challenge as football can present: a hugely attritional contest played out to the relentless, infernal sound of Iranian vuvuzelas, which drowned out any means of communication or thought.
It was just as well that Spain had the man for such a test. Diego Costa’s goal, just after half time, came as you wondered whether they had what it took to knock down the door built by Iran in a partisan atmosphere straight out of central Tehran.
The goal was not an object of beauty but the winners of this tournament will need much more than artistry. Someone had brought a banner which read ‘Iran 0 Spain 0’ because even the thousands of Iranians who swarmed up the walkways with their vuvuzelas knew what the game plan would be.