Read football journalist and author Guillem Balagué's thoughts on Spain's remarkable defensive record at the World Cup.
Historically it has mostly been Spain's devastating midfield and innovative attack that has grabbed the headlines as they carried La Roja to glory.
But could it be the defensive prowess and downright stinginess of Luis de la Fuente's latest Spanish side that will help them return to the World Cup winners podium?
Unai Simón's unbeaten streak has now reached 609 minutes since Ao Tanaka of Japan beat the Athletic Club goalkeeper at Khalifa Stadium during the Qatar World Cup. The run has been extended to an incredible length in the five matches of this summer tournament.
Spain coach, De la Fuente, is, as always, desperate to make it clear that it is not just about the goalkeeper but always about the team. This is a record built on the work, solidarity, generosity and supreme efforts of all of his team mates something that Simon was keen to insist on when the Athletic Club keeper claimed that, "the record speaks more highly of the team than of me,"
The numbers back up Unai and De la Fuente's analysis. In the group stage, Spain only conceded 14 shots against Cape Verde, Saudi Arabia, and Uruguay. Unai Simón only had to make four saves.
In the knockout stages, when the pressure increases, Spain remained unfazed. They were just as solid.
When they met Austria, their opponents failed to register a single shot on target out of five attempts. Portugal put the defence under more pressure: 10 shots, but only two on target.
But as unwilling as De la Fuente is to highlight individuals preferring instead to focus on the team collective, it is impossible not to notice the devastating effect Rodri is having on Spain's performances.
Rodri rounded off a perfect performance when he set up Ferran Torres to provide the golden assist for Merino to finish and send Spain one step closer to dreamland. But his influence went beyond the fact he is the player that covers the most ground for Spain.
If La Roja was an organized and confident team, it was largely thanks to the Manchester City player who has shown again to be a leader in a high-stakes match.
No one was more involved in the game than him (106 touches, far ahead of Cubarsi, second with 82), and he also led in completed passes: 87, with a 92.5% success rate. A masterclass.
How about Spain’s main star? Some erroneously believe 18-year-old Lamine Yamal was relatively ineffective against Portugal, an opinion dismissed by former Arsenal coach Arsene Wenger who was swift to say that football is not only about goals or assists; it is about the influence a player has on the game.
He added that Portugal devoted a great deal of attention to Lamine Yamal. They consistently doubled up on him, and that alone tells you they recognised the threat he posed.
For De la Fuente the Portugal match was the most important match of the career of the young striker who turns 19 on Sunday, that he will learn of what he did against Portugal, continuously trying to beat his defender (Nuno Mendes got injured possibly because the intense efforts of Lamine) and tracking back when the team needed it.
Are we going to see the Lamine Yamal ‘moment’ as we edge ever closer to the final stages? I think we could. And the bad news for Belgium perhaps, is that so does he!
After the Portugal game the youngster announced that, “the closer the important matches get, the semi-finals or the final, the better I play. I've never been the best player in the group stage. I'm comfortable with that. I know I have opportunities to prove it, and I hope the match against Belgium will be a great one for the whole team.”
Spain has reached the quarter-finals after eliminating one of the favourites. And they did so without playing their best football and with their stars hampered by injuries. Lamine isn't at 100% and Nico is still being carefully monitored. Fortunately for them, the midfield was solid and the defence impeccable.
Defence and a sharper Lamine will be crucial, but let me add a third element that has helped Spain, something that has set De la Fuente aside: his ability to make crucial changes from the bench.
When, against Portugal, he took off Olmo, Spain's best player on the field, to bring on Mikel Merino, it seemed like a change that was hard to justify. Not because of Merino's abilities, but because of the decision to leave Olmo out.
But it worked just as it did when he made the right call by bringing on Ferran. The Barcelona player redeemed himself, if he had any reason to do so, contributing with his mobility and determination, this time accompanied by a touch of finesse.
