Wikipedia
Fla–Flu ( truncation of Flamengo- Fluminense) is an association football match between cross-town rivals Flamengo and Fluminense. Matches take place in the 78,000-seat Maracanã Stadium, located near downtown Rio de Janeiro, in the city's Maracanã district. The world record football match attendance between clubs is a Fla 0-0 Flu with 194,603 (177,656 paid) in 1963.
The moniker Fla–Flu was coined by the journalist Mário Filho during the professionalization of Rio de Janeiro's football.
Flamengo is the most successful team in Rio State Championship by one championship. Flamengo has won it 33 times while Fluminense has won 31. Flamengo has won 6 Brazilian National Championships, as defined by the CBF, the 1987 Copa União (an independent league organised by the Club of 13) and 3 Brazilian Cups. Fluminense has won 4 Brazilian National Championships and 1 Brazilian Cup. Fluminense has won the Copa Rio, which it claims to be equivalent to an intercontinental club tournament. Flamengo has won one Libertadores Cup and one Intercontinental Cup, both in 1981. Fluminense is the only team in the world that holds the IOC's Olympic Cup ("Coupe Olympique" or "Taça Olímpica"), a non-competitive award for distinguished service in upholding the ideals of the Olympic Movement and to recognise the particular merits of institutions or associations and their services rendered to sport, conquered in 1949.
The rivalry between these two clubs began in October 1911, when a group of dissatisfied players from Fluminense left the club, and went to Flamengo, which at the time had no football department. The first Fla–Flu ever was played the following year, on July 7, 1912 at Laranjeiras stadium. Fluminense won this match 3-2, with 800 people in attendance.
The Fla–Flu matches are mentioned in Lamartine Babo's unofficial, but very popular, Flamengo anthem composed in 1942.