If football was determined by statistics, Fernando Hierro's men would have won at a canter. By this game's end Spain had enjoyed almost three times as many efforts on goal as Iran, not to mention 78% of possession.
Goals are the only currency worth holding in this sport and, mercifully for Hierro, Spain came out on top there too. Yet for all they were continually in the ascendancy, they found themselves separated from their far less illustrious opponents by a single deflected effort off the shin of Diego Costa.
That is not to Spain did not deserve their win. But the efforts of Carlos Queiroz's Iran side should not go unnoticed: they made this a very tricky evening for many people's favourite to win this year's World Cup.
Here are five things we learned from a fascinating evening in Kazan.