The Copa Libertadores final that ended up in Madrid

CONMEBOL confirmed the relocation on the days after two postponements had already stalled the tie. Alejandro Dominguez, the CONMEBOL president, announced the second leg would be played at the Santiago Bernabeu in Madrid, framed partly as a way to let supporters of both clubs attend. Both clubs objected furiously. So did their supporters and senior figures in Argentine football.

The cause was an attack on the Boca Juniors team bus on 24 November 2018, before the scheduled second leg at River's Estadio Monumental. Some River Plate supporters threw objects at the bus on its way to the ground. Windows were broken. Police fired pepper spray. Several Boca players were taken to hospital. The match was postponed twice before CONMEBOL removed it from Argentina entirely.

The first leg had finished 2-2 at Boca's ground, leaving everything open. The second leg, now transplanted to Madrid, was played on 9 December 2018 — roughly 10,000 kilometres from either club's city. River Plate won 3-1 after extra time. On aggregate, 5-3. River's fourth Copa Libertadores title.

Marcelo Gallardo, River's coach, did not soften it. "We're going to play the Copa Libertadores 10,000 kilometres away," he said, and added: "Someday we're going to rethink what just happened, and we're going to remember this as a total embarrassment." Those words came from the man who won.

Argentina's president, Mauricio Macri, said the attack was "a tough blow" and that it "must lead us all to reflection".

An estimated 25,000 supporters of each club were expected at the Bernabeu. CONMEBOL had set aside 10,000 tickets for travelling Argentine fans — 5,000 per club. Neither club sold its full allocation. The unsold tickets were returned to CONMEBOL. A journey of more than 10,000 kilometres, arranged at a few days' notice in December, put the trip beyond the reach of most of both supports. The final had been moved, among other reasons, so that both sets of fans could be there; thousands of the seats reserved for them were handed back.

About 4,000 police were on duty. Supporters of the two clubs sat alongside each other on the long sides of the stadium. In Buenos Aires, that is not possible: away supporters have been barred from Argentine domestic league matches for years. In Madrid, on 9 December 2018, it passed off without incident.

River Plate lifted the Copa Libertadores in a stadium belonging to neither finalist, in a country neither club plays in, watched by a crowd that included thousands of empty Argentine seats.