It was a strange afternoon in Moscow.
Taking an early lead as the bulldozing Sergio Ramos distracted veteran defender Sergei Ignashevich enough for him to score an unfortunate own goal, Spain took the driving seat and looked certain to progress.
But they coasted along, satisfied to keep the ball and protect their lead, rather than double it. On the balance of play, it resembled a team 3-0 up in the 80th minute.
Russia didn’t look dangerous but were always in the tie with a goal between them, and Spain were made to pay after Gerard Pique stupidly handled the ball in plain view of the referee.
Spain paid a heavy price for their conservatism and were utterly abject at creating chances. The introductions of Andres Iniesta and Rodrigo improved things, but they remained static, unable to force a breakthrough.
Russia were compact and organised while they showed unbelievable stamina to compete to the end. Scoring all their penalties in the shootout, they are worthy of their place in the quarter-finals.
Here are five things we learned:
1 Turns out a manager is important - who knew?
When Julen Lopetegui was sacked on the eve of the tournament, there was a lot of discussion about Spain's ability to self-manage, and follow the template he left behind.
Considered one of the pre-tournament favourites, they were responsible for some of the most complete and impressive performances in the build-up to Russia - not least a 3-0 win over Italy to seal qualification.
The magic appeared to still be there in the opening game as Spain were excellent for the vast majority of the tie against Portugal, looking incisive and creative, and only drawing due to the individual masterclass of Cristiano Ronaldo.
But it wore off as the tournament went on as the new coach Fernando Hierro began to have more of an influence.
Having achieved little as a coach, his natural conservatism wasn't right for this team, who had to show more endeavour against the compact defenses of Iran, Morocco, and Russia.
Severely lacking in game management, the Spanish FA should rue their decision to sack Lopetegui, the architect of a genuinely brilliant international side. It turns out Hierro was the wrecking ball.
2 Russia can go the distance against any team
Playing with so little of the ball, it's hard to judge Russia as a footballing side. But they showed they've got the stamina to go the distance against any team.
The tiki-taka style of Spain coined the term "death by passing" and that was often the key to grinding down teams in their period of domination between 2008 and 2012. Completing over 1000 passes here, the Russians would still not be ground down.
This was never more evident than when Golovin, on from the start, out-sprinted late Spain substitute Rodrigo in the 117th minute.
The running stats from the group stage has invited a certain degree of scepticism about how they're able to cover so much ground. Regardless of the reasons, the reality is this Russia team will run until the end.
With an organised backline and confidence building, they will believe in their ability to grind out a draw or a narrow win over 90 minutes. Or 120, if need be.
3 This World Cup is incredibly open, adding extra edge.
The outcome of Russia knocking out Spain means that one outsider is guaranteed to be in the final: Russia, England, Colombia, Croatia, Sweden or Switzerland.
On that half of the draw, there's extra meaning and value in each and every knockout encounter. Each of the six teams will fancy their chances and know this is an opportunity that will never come around again.
Perhaps this was the reason for Croatia and Denmark freezing and appearing to play within themselves, knowing what was at stake. Hopefully, the likes of England and Sweden won't follow that template.
4 De Gea, Pique and Ramos show international football is about more than pedigree
Sergio Ramos has won the Champions League as Real Madrid captain three times in a row.
Gerard Pique has two trebles to his name at Barcelona and has shown an ability to step up since the retirement of his old partner, Carles Puyol.
David de Gea has a highlights reel of ridiculous saves over the last season and is regarded by many as the best goalkeepers in the world.
But individually and collectively, they were shambolic. De Gea made one save all tournament and was culpable with a horrendous error against Portugal.
Ramos has looked unsure all tournament, and his mix-up in possession allowed Morocco in to score against them.
Pique made a series of blunders and was brainless in committing the handball that allowed Russia to equalise.
The centre backs didn't appear to trust the goalkeeper behind them. They didn't understand one another, either.
It goes to show that organisation and understanding is more important than sheer pedigree in international tournaments.
5 Russia emulating South Korea in 2002 may not be a good thing
2002 is not a World Cup remembered fondly.
Alongside the eventual champions Brazil, the semi-finals featured a good but not remarkable Turkey, an average Germany side and a South Korea side who mined the advantage of the home advantage for all it was worth and were fortunate with several key officiating decisions on the way there.
There's a danger of this World Cup going the same way.
There has been immense drama so far in this tournament. The likes of Spain, Germany, Portugal, and Argentina have deserved their early exits, but the best talents in world football failing to click is not something to celebrate. Especially as those who topple them have shown little more than basic organisation nous.
There's a danger that the latter stages will lack real quality. Russia, like South Korea before them, have heart but are ultimately a rudimentary footballing side.
Listen to the RealSport football writers discuss all the action from Day 15 of the World Cup in Kremlins in the Basement: RealSport’s daily World Cup podcast.
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