Making no attempt to play football that delights the crowd, for 50 minutes Iran played the ugly game to perfection, every man behind the ball and crowding the goalmouth, to the frustration of a star-studded Spain on Wednesday evening.
In fact, they forced the billion dollar Iberian line-up to get sucked into their game; gone was the flair and class we saw in the Spain vs Portugal 3-3 first round thriller.
The bull was outwitting the matador and a Spanish inquisition was looming as to why they could not find the back of the net with over 70% possession in the first stanza.
However, when the teams reappeared after the break, Spain upped the pace and the pressure was on the Iranians.
A goal was imminent and it came in the 61st minute when a panicky clearance rebounded off the knee of Diego Costa and into the net.
It was his third of the tournament, matching the tally of Ronaldo, and he could care less how it came.
Chances came and went at both ends after that; in fact, Iran had the ball in the back of the net only for the VAR team to determine an offence, and the match was decided on a solitary goal.
So, with each side to play their third and final Group B game, it is Spain and Portugal on four points with Iran on three.
Spain will take on already doomed Morocco and should breeze through, while the Portugal v Iran encounter will decide which of the two progresses to the last 16.