Jorge "Koke" Resurreccion and Iago Aspas eventually missed their shots and Russian Federation prevailed.
The U.S.is the only nation with two referees at the World Cup. "We'll be back. It's been a very long season but I hope I can be at the next one".
The 1-1 draw (4-3 in PKs) marks the first time Russian Federation has reached the quarterfinals of the World Cup since 1970, when it was known as the Soviet Union.
Remarkably, though, Stanislav Cherchesov's charges are now just two wins away from the World Cup final.
"It's very hard", Ramos said. Instead, Artem Dzyuba levelled the scores from the penalty spot before half-time as La Roja were continually frustrated in their attempts to break down the hosts' well-manned rearguard.
Colombia, whose best finish was their run to the quarter-finals in Brazil four years ago, take on the English in the last round-of-16 match later the same night in Moscow.
Spanish midfielder Andreas Iniesta thanks the crowd after the game.
"It's a reality that this is my last game with the national team, on a wonderful stage", Iniesta told reporters after the defeat.
Tens of thousands of fans in the capital's Federation Internationale de Football Association fan fest crowded around several huge screens as they witnessed what many of them would have believed unthinkable before the match.
But Putin's decision not to personally attend Russia's first World Cup knockout game in the post-Soviet era fed suspicions that the Kremlin believed the team would lose.
"This is a great victory for us, for the whole country, the soul of the country", Mikhail Sitner, 34, from Moscow, said.
The Russians never stopped running - not even 38-year-old Ignashevich and surely they exceeded their tournament average of 110km covered - and maybe Spain were banking on them to tire in the extra 30 minutes. I've already said it a lot of times.