The Brazilian FA endorsed Mário Filho's idea, and organised the competition with a view to creating a Club World Cup.

FIFA president Jules Rimet made statements praising and bidding good luck to the initiative of the Brazilian FA.

In 1951, there did not exist the FIFA Ranking, nor any "qualification tournament" for clubs to qualify to intercontinental club competitions (from 1960 on, the UEFA Champions and Libertadores cups would serve as "qualification tournaments" for the Intercontinental Cup), so in 1951 the organisers of Copa Rio (the Brazilian FA, Ottorino Barassi, Stanley Rous, Mário Filho) had to rely on their view of football history (mainly the FIFA World Cup history) in order to elect which were the strongest national football leagues of the world, whose champion clubs would be invited to Copa Rio.

According to Brazilian newspapers O Estado de São Paulo and Jornal do Brasil, and Spanish newspaper El Mundo Deportivo, the original 8-club plan of the Brazilian FA (organiser of Copa Rio) was to organise the competition with the reigning champion clubs of the Rio de Janeiro and São Paulo state Leagues (the first Brazilian national cup, named Taça Brasil, was not established until 1959, and the Rio de Janeiro and São Paulo state leagues were – and still are – the strongest state leagues in Brazil), as well as the reigning club champions from Uruguay, Italy, Spain, England (participants at the 1950 FIFA World Cup, held in Brazil, not to mention the status of Uruguay and Italy as former FIFA World Cup Champions and England as the founders of the sport), Portugal (the Portuguese champions were invited in order to please the huge Portuguese community living in Rio de Janeiro and São Paulo) and Scotland (based on Scotland being as successful as England in the British Home Championship).

Some other countries were briefly considered by the Brazilian FA as possibilities for Copa Rio (as Sweden, 3rd place in the 1950 FIFA World Cup whose champion Malmö FF was not invited as the club had not pleased the Brazilian football audience in a former visit to the country), but the final plan of the Brazilian FA for the organisation of Copa Rio ended up consisting of an 8-team cup with the reigning champions (1950 South American season and 1950/1951 European season) of Rio de Janeiro, São Paulo, Portugal, Spain, England, Scotland, Italy and Uruguay.

The Rio de Janeiro, São Paulo, Portugal, Uruguay, Yugoslavia and France representatives were the reigning (the then current) champions of their leagues.

In 1952, no British, Spanish, French or Italian clubs accepted the invitation to participate in Copa Rio: Juventus, AC Milan, Internazionale, Hibernian, Newcastle United, Manchester United, Barcelona, Real Madrid and Nice were all invited to participate in the 1952 Copa Rio, and all of them declined.

As there was proximity of dates between Copa Rio and the Latin Cup (and the European clubs were obliged to grant vacation to their footballers after the end of the European season), 2 clubs in 1951 (AC Milan and Atlético Madrid) and 3 in 1952 (Barcelona, Juventus and Nice) declined participation in Copa Rio supposedly in order to prioritise the Latin Cup.

In at least five European countries (Switzerland,[15] Austria,[16] Spain,[17][18][19] Portugal,[20] and Italy), the competition was hailed as either "Club World Championship/Cup" or simply as "Champions Cup".

Among the European countries originally envisaged to be represented in Copa Rio, Portugal was chosen in order to please the huge Portuguese-Brazilian community, not due to football-based criteria.

The same newspaper also sustained that competitions such as Copa Rio should ideally be organised by FIFA, in dates set and announced by FIFA in due advance, as there was the perception that the dates set by the Brazilian FA for Copa Rio did not fit the interest of the European clubs, thus resulting in a number of them declining to participate.

As the final list of the 1951 participants turned out to be not of the same quality of the original plan, this fact was also criticized by the Italian press; as an example, Vittorio Pozzo wrote an article criticising Copa Rio for not featuring representatives of Argentina, Scotland and England (the Brazilian newspaper Jornal dos Sports criticised him back, stating that the 1934 and 1938 World Cups won by Italy under Pozzo's guidance did not feature Uruguay, Scotland and England either).

Italian newspaper Corriere dello Sport stated in 1951 that, after the declination of Spanish, English and Scottish clubs to participate in Copa Rio, the competition "was reduced to an ad inviti cup".

Probably as a consequence of these facts, only 3 Brazilian newspapers (amongst 15 researched) referred to the 1952 edition as being the "World Champions Cup" (compared to all of 15 Brazilian newspapers researched on the 1951 edition): these were Mário Filho's Jornal dos Sports, Última Hora (also connected to Mário Filho, as his brother headed the sports section) and Diário - Minas Gerais (soon after the 1952 cup, Mário Filho wrote an article being sorry that the Brazilian audience regarded the 1952 Copa Rio as being of a lower technical level compared to the 1951 one, and being sorry that, while in 1951 Palmeiras hailed themselves as club world champions after winning Copa Rio, Fluminense did not regard their 1952 conquest in the same manner).

Rot-Weiss Essen (West Germany) and Partizan (from Belgrade, Serbia, then Yugoslavia) were invited and accepted to participate but were then uninvited by the Brazilian Sports Confederation.

The main European attraction of the 1953 cup was Hibernian, a club that, as Scottish champions, were among the first to be invited to both editions of Copa Rio (1951-1952), and had declined on both occasions.

The 1953 edition featured Nacional (its eventual champions), Peñarol, Botafogo, First Vienna, Fluminense, Colo Colo, Dinamo Zagreb and Presidente Hayes, and the 1954 one featured Peñarol (its eventual champions), Nacional, Fluminense, America, Rapid Wien, Alianza Lima, Norrköping and Sportivo Luqueño.

Ottorino Barassi's 1955 words resonate for example the Latin Cup, organised jointly by the national FAs of all the 4 participating countries.

A number of requests for official FIFA recognition, or acknowledgment (thenceforth the expressions "recognition"/"recognise" will be used in this text), of Copa Rio as an officially recognized "club world champions-crowning" tournament have been made to FIFA, primarily by 1951 Copa Rio winners Palmeiras and the Brazilian FA (nowadays named CBF- Confederação Brasileira de Futebol).

Since 2007, the issue has turned into a matter of controversy: on the one hand, Copa Rio was unquestionably created in order to determine the "club world champions" and Palmeiras was celebrated in this manner in Brazil in 1951 (as proved by the 1951 Brazilian newspapers); on the other hand, the competition fell short of the aim of representing the best of European and South American football, as can be seen through the list of clubs that were invited and declined to participate.

In 2006, Palmeiras prepared a document for FIFA, detailedly describing the 1951 Copa Rio, in order to request official confirmation of their conquest as the first ever club football world championship.

[note 4] Barassi was involved in the recruiting of European clubs also in 1952, and also in its 1953 successor-tournament, though only through telephone contact, with no evidence that he came to Brazil personally in 1952 and 1953, as he did several times for the 1951 edition.

A Liminha-inspired Palmeiras edged a Juventus team including Giampiero Boniperti & a Danish triumvirate to become the sport's first intercontinental world club champions.

This is the case of tournaments involving European and South American clubs, such as the pioneering Copa Rio, played in 1951 and 1952, and the Intercontinental Cup.

The eight-team competition involved some of Europe’s top teams, Uruguayan behemoths Nacional and Brazilian duo Vasco da Gama and Palmeiras, who qualified as Rio-Sao Paulo Tournament winners.

The duo’s status as favourites was strengthened in the group stage, with the Carioca colossuses thrashing Sporting Lisbon and Austria Vienna 5-1 and the Turin titans thumping Palmeiras 4-0.

The Paulista powerhouses, however, had other ideas and, brushing aside injury blows, beat Vasco 2-1 over 180 minutes in the semi-finals and stunned Juve 1-0 in the first leg of the final.

Rio de Janeiro was packed on the day of the decider, with a reported 10,000 Italians cramming into its hotels, certain Juventus would emerge triumphant.

Yet Liminha, a 21-year-old who had begun the tournament on the bench, helped set up the first equaliser and scored a late, title-clinching goal in a 2-2 draw in front of over 100,000 at the Maracana.

The tournament also featured teams from Europe and South America and had a similar format than its predecessor, being also held in Rio de Janeiro and São Paulo from 7 June to 4 July.