If there was one fleeting image, one defining moment, to sum up the quarter-final clash between Spain and Iran, it came midway through the first half in Kochi.

With all of Spain's outfield players camped near the Iran box, goalkeeper Alvaro Fernandez took the opportunity to stroll up the pitch and set base at the halfway line, stretching his arms and legs while he savoured the game from the best seat in the house.

It's always fascinating to piece together what goes on inside a keeper's mind on days like Sunday. When his team is so dominant on the ball, so completely in control of the match, he may just as well have been one of the record-high 28,436 people watching from the stands at the Jawaharlal Nehru Stadium.

On days like Sunday, Iran, too, may just as well have not turned up. And they almost didn't, till late in the second half. It felt like an obligatory cameo tacked on at the end of the show, just to keep people from walking out, because by then the main event was well and truly over.

In many respects, it was over before a ball was even kicked. Iran entered the quarter-final as the joint top-scorers, having won every single game in the lead-up, including a 4-0 thrashing handed out to Germany. But they were up against a Spanish team still snarling from an early defeat to Brazil, and who were at the top of their possession game. Iran were up against a group of youngsters who had a winning mentality and philosophy ingrained in their blood and that had been passed down in their country in team after team, for decade after decade, to generation after generation. It was a mismatch from the word go.

It can be a torturous experience playing against a team at the peak of its passing powers. You're led to a false sense of security, believing that so long as you hold your line together, you can keep out even the most dangerous of apex predators. But what you don't realise is, you're being hunted and slowly picked apart one by one, as you've already been lured to take the bait.

Iran's bait was a nice, juicy opening through the middle of the pitch to launch a counterattack. It gave them the illusion of survival, and with Spain choking the living daylights out of every Iranian outfielder with their intense pressing, hoofing out to no-man's land was the Asian side's only option to breathe.

With more and more Iranian shirts being seduced to chase after Spanish shadows, the spaces suddenly opened up on the wings, and Ferran Torres capitalised, sending in cross after dangerous cross from the right till Abel Ruiz finally converted the opener.

Not even 12 minutes in, and Iran's strategy had already gone out the window. They had been hoping to keep it tight, and hit Spain with their quick transitions from defence to attack. But the early goal meant they'd have to venture out and take more risks, increasing the likelihood of Spain completely devouring them.

It was all part of an elaborately laid out plan, as head coach Santiago Denia would later say.

"We did our job almost perfectly," he said. "We knew it was important to begin the match very well. Playing through the inside of their defence was difficult, so we had to go wide. We had chances to score the second goal in the first half, but eventually they had to move forward in the field, giving us more chances and spaces. We wanted to be vertical and move the ball forward in the field. That's the idea I wanted the team to have."

But that's still easier said than done. For Spain's plan to work without a hitch, each and every player had to be technically proficient with the ball, and mentally aware of his surroundings without it.

Each pass had to be concise and purposeful. Runs had to be made to drag defenders out and create space. Triangles were formed between full-back, winger and midfielder to trap Iranian bodies chasing after the ball. Nothing could be left to chance. Nothing was left to chance.

Spain had multiple avenues of attack. On the wings, Sergio Gomez and Ferran Torres were a handful, feeding Ruiz and Cesar Gelabert with chance after chance. At the centre, Mohamed Moukhliss and Antonio Blanco had everything covered, playing through balls over the top. Iran simply couldn't keep up, and they ended the first half with 20% possession, and no shots registered on or off target.

"We did not start the match good and well," Iran's coach Abbas Chamanyan said after the game. "We were not good in attacking positions in the first 20 minutes, and unfortunately we conceded, which caused many problems. We must not forget that Spain are excellent and a high-quality team. We gave Spain too much respect. Our players are still young. They probably got overawed by just the name Spain. After the second half, we tried harder, but it was hard to establish a connection between defence and attack."

Spain continued their domination even in the second half, passing circles around the Iran midfield. And as if just to flaunt their creative muscles even more, they started to mix it up, blending possession, individual skill and counterattacking football with utmost precision and panache. It led to two more goals that were different in fabric, but just as impressive in quality.

The first was a long-range screamer by Gomez, his left-footed drive nestling into the top corner of the net. The second was a lightning-quick break down the right, featuring full-back Mateu Jaume, playmaker Gelabert and winger Torres, with the latter putting the finishing touch to send Spain flying into the semis, where they will face Mali.

Iran did eventually get a consolation goal for all their labour and efforts, but it was too little too late. Three-One. Spain hadn't just defeated Iran, they had crushed them, laying down the marker for all the remaining teams in the tournament.

Interestingly, every Spanish youth player is required to dedicate at least an hour a day in India to academic work, to ensure their education isn't affected during the World Cup. It's difficult to say what their grades are like in school, but on the pitch, every Spanish shirt passed with flying colours.