The biggest match in the history of the tournament that was named in honour of those who liberated South America from Spanish colonial rule, was to be played in the Spanish capital.

Originally scheduled for 24 November in Buenos Aires, the second leg of this meeting between city rivals Boca Juniors and River Plate was postponed when Boca's bus was attacked by River fans on its way to the stadium. Boca players suffered cuts from broken windows and were also affected by the tear gas used by police to disperse the crowds.

After a second attempt to play the game was also aborted a day later, Conmebol, which runs South American football, felt security was more reliable in Madrid than any of its other nine non-Argentine member countries.

Alejandro Dominguez, the Paraguayan head of Conmebol, said it was "an exceptional decision in exceptional circumstances".

He felt that the large number of Argentine expats in Spain would maintain the unique atmosphere of the Superclasico, albeit thousands of miles away from Buenos Aires.

Only 4,000 fans from each club travelled from Argentina because of the prohibitive cost of flights and match tickets, which were much more expensive here than they were for the postponed fixture.

This was the Superclasico, a derby whose romanticised fierce and - as was proven in Buenos Aires - violent nature is legendary around the world.

Yet, despite their best and loudest efforts, the voices of Boca and River fans were at times muffled by the murmur of casual observers inside the Bernabeu.

It felt like a fudged final. The unfettered raw emotion of South American football was swaddled in European practice and procedure.

Fans of River Plate felt aggrieved because they had lost home advantage, and football supporters throughout South America felt betrayed.

Mauro, a 39-year-old River supporter who lives in Barcelona, spent the relatively small amount of £180 to go to Madrid.

But this was after he had spent £1,500 on a two-day trip to Buenos Aires to see the match that never was.

"I'm really annoyed because it's a game that we're supposed to play in South America. Boca played in front of their fans but we can't," he said.

Nico, a fellow River Plate supporter, also felt cheated out of watching an authentic match.

"For me it's embarrassing," he said. "I wanted to watch the match with my parents and my brother in River's stadium, but we couldn't. Sharing this with them was the biggest dream of my football fan life."

Hernan, a 44-year-old Boca Juniors fan from Buenos Aires, saw the move to Madrid as a betrayal of the history of the competition but not one that diminished his anticipation.

"It's very bad that it's here," he said. "It should be in River's stadium. This Copa Libertadores final needs to be played in Boca or River. To play here is crazy."

But for Lucas, an Argentine living in Alicante and bizarrely wearing a half-and-half scarf, showing the colours of both the bitter rivals, this was a chance not to be missed.

"Thanks to the bad decisions made in South America, Argentines living here are very lucky," he said.

"I went to see Boca play a friendly in Barcelona in August but an official match? The last time I was in the stadium was for the 2000 Libertadores final."

South America is hoping to host the 2030 World Cup and South American football chief Dominguez thinks that bid is still realistic despite the attack on the Boca Juniors bus.

But as he looks at how to avoid a repetition of such a shameful incident, other administrators may see the staging of the match in Madrid as an interesting precedent.

Next week, a Spanish court will rule on La Liga's appeal to hold a match between Girona and Barcelona in Miami, Florida in January.

Luis Rubiales, the president of the Spanish FA, is against it and Fifa president Gianni Infantino said he was "frontally opposed and I deny permission".

But, along with Real Madrid president Florentino Perez, Rubiales played a crucial role in moving the Superclasico to the Bernabeu.

And Sunday's match is the latest in a developing string of seemingly unconnected events since the World Cup which are all related to the controversial notion of playing games away from their usual territories.

A trio of Spanish Real Madrid fans from Cordoba who were at the Bernabeu for River's 3-1 second-leg victory - a result which secured a 5-3 aggregate win and the trophy - thought a Champions League final on another continent would not be as controversial as the match in Madrid.

"We are very excited because Spain has many connections with Argentina and we have the opportunity to live a big, special game," said Ignacio.

"As for the Champions League, they already play the final in different countries so it won't be so strange."

Pablo agreed. "They played the last Champions League final in Kiev, so for us it's normal if it's in Kiev, Dubai or somewhere else.

"The only thing that will be annoying will be the extra travel."

The question is: was the extraordinary spectacle of a Copa Libertadores final in Europe a genuinely exceptional event, or could it be a sign of things to come as football authorities seek to exploit the game's global appeal?