UEFA on Monday said it had "reluctantly" approved the staging of a LaLiga and a Serie A match in the United States and Australia respectively despite fan protests.
"While it is regrettable to have to let these two games go ahead, this decision is exceptional and shall not be seen as setting a precedent," UEFA president Aleksander Ceferin said in a statement.
UEFA made its ruling after Spain's LaLiga agreed to move a game scheduled for late December between champions Barcelona and Villarreal to Miami, Florida.
Italy's Serie A also decided to stage the encounter between AC Milan and Como on February 8 in Perth, Australia, to avoid a clash with the Winter Olympics opening ceremony at Milan's San Siro stadium.
But that sparked protests from European supporters groups who branded the moves "absurd, unaffordable, and environmentally irresponsible".
In its statement, UEFA said that it had "reiterated its clear opposition to domestic league matches being played outside their home country".
But despite "the widespread lack of support that had already been raised by fans, other leagues, clubs, players and European institutions", UEFA said that it had found no clear regulatory framework in FIFA's statutes that would allow it to oppose the moves.
"The UEFA Executive Committee has reluctantly taken the decision to approve, on an exceptional basis, the two requests referred to it," European football's governing body said in its statement.
NFL, NBA PRECEDENT
While the idea of relocating European football matches to other continents seems shocking to many, other sports – particularly US ones – have been doing something similar for years, even decades.
The NFL has held games in London since 2007 while it also expanded to Mexico and Germany.
Last year it added a game in Sao Paulo and this year there has been one in Dublin for the first time. Another is slated for Madrid in November while Melbourne will play host to a game in 2026.
The NBA, which has relocated regular-season matches since 1990 to Japan and since 2013 to Europe, has already scheduled six games in Berlin, London, Manchester and Paris over the next three seasons.
In rugby union, the French Top 14 club competition took its 2016 final to Barcelona's Camp Nou stadium, while Ireland and New Zealand played an international match in Chicago that same year – with Ireland claiming their first ever victory over the All Blacks.
Last weekend, Argentina played their final Rugby Championship match at home to South Africa at Twickenham in London.
It is not unheard of in football to host matches abroad, but until now those had only ever been glorified friendlies.
The Spanish and Italian Super Cups are already held in Saudi Arabia, after previous editions in China, Morocco, Qatar and Libya, as governing bodies seek to cash in on the global reach of the beautiful game.
LaLiga has been trying for years to host games in the United States, home of its commercial partner Relevent Sports.
Football's world governing body FIFA shifted its hitherto opposition to relocating matches, with a 'working group' launched in May to revise their rules.
That opened the door to UEFA granting LaLiga and Serie A the permission to branch out.