The atmosphere in the build-up to a Copa Libertadores final is always intense. But when you throw in two finalists that have never previously won the prestigious trophy, as is the case with Fluminense and LDU, and set the decisive second leg in Rio de Janeiro's legendary Maracana stadium, the results are nothing short of spectacular.

Brazil's most famous city, boasting around six million inhabitants, is no stranger to big footballing occasions. Calling Rio home are no fewer than four giants of the Brazilian game in the shape of Botafogo, Flamengo, Fluminense and Vasco da Gama, and the supporters of Flu's main local rivals are making sure they are not left out of the party.

Though it is true that most of the flags and banners adorning the coastal metropolis are in Fluminense colours, fans of the city's remaining sides have pledged their support for Ecuadorian visitors LDU, lending the final's return leg a somewhat peculiar ambience. Perhaps the most obvious explanation comes from a survey carried out by the Datafolha Institute in January, which discovered that 43 per cent of Carioca football fans follow Flamengo, compared to a mere 11 percent for Fluminense.

Witnessing this phenomenon first hand is Gabriel Silva, one of a number of street vendors to have spent the last few days selling flags to passing car drivers. "I've brought loads of Fluminense ones with me, some Flamengo ones and also a few LDU flags, which are a really popular with Flamengo fans," he told FIFA.com.

And the LDU squad also received a clear indication of this unexpected wave of support when taking the field for Monday's training session at Flamengo's Gavea stadium. Dozens of Flamenguistas were there to meet the Ecuadorian players, waving banners that read 'LDU: Liga Deportiva Urubu', urubu being the Portuguese word for 'vulture', the symbol of Flamengo.

Once the session was over, the Fla supporters gave a particularly warm send-off to LDU's Joffre Guerron, who they claimed bore a striking resemblance to Rubro-Negro favourite Obina. The bemused Ecuadorian was even presented with a Flamengo shirt, which he gamely wore while giving a number of interviews and having his photo taken - an episode that has not gone down too well in the Fluminense ranks.

All still to play for
Turning to matters on the field, the destination of the Copa Libertadores trophy remains in the balance, despite LDU recording an impressive 4-2 first-leg win at their Estadio Casa Blanca. The Ecuadorians were clearly unhappy at not building a more comfortable lead to take to Brazil, understandable given Fluminense's record at the Maracana during this year's competition. O Tricolor Carioca have won each of their six games at the mythical venue, including triumphs over tournament favourites Sao Paulo and Boca Juniors in the last eight and semi-finals respectively.

Any Tricolor fans that aren't in the Maracana this Wednesday will regret it forever. It's our big chance to join the world footballing elite
Fluminense fan Marcelo Souza, 19, explains why missing tonight's game was never an option to him.

It is hardly surprising, therefore, that the 69,000 tickets available sold out within a matter of hours, with many fans spending the night queuing outside the ticket office. " . And if Sao Paulo and Boca couldn't stop us, I can't see LDU managing it," says 19-year-old student Marcelo Souza, clutching his prized match ticket. "And we mustn't forget that if we win tomorrow we'll go level with Flamengo," he added, in reference to Fla's solitary Libertadores triumph in 1981.

Even the Laranjeiras side's defeat in Quito has not dampened the faithful's devotion to their team, with thousands attending training to show their support for Renato Gaucho's men. "Thiago Neves' goal (Flu's second in Quito) and Fernando Henrique's save that prevented LDU scoring a fifth have made me feel certain that we'll be champions," said the coach himself. "The Flu supporters are intelligent and they realise this too. That's why they never turned on us."

Ecuadorians for a day
Over in the opposing camp, the hotel housing the LDU delegation is clearly proud to have been chosen as the Ecuadorians' official base in Rio. Not only does the building exhibit a huge Ecuadorian flag, but many of the approximately 1,000 fans that have travelled from Quito to watch their team have booked rooms in the hotel - leading to an intriguing mix of players, supporters, club directors and accompanying journalists congregating together in the foyer.

"We're part of a group of fans that follow Liga's matches all around Ecuador, and we just couldn't miss out on an occasion like this," said LDU die-hard Miguel Arauz. "Given the circumstances, this was always going to be special. But once you feel the footballing fervour here in Rio de Janeiro, you can see that this experience will be out of this world."

But as the team coach taking LDU to the Maracana for their final pre-match training session leaves the hotel to hearty cheers and applause, not all of those present are from Ecuador. Indeed, local boys Mateus and Pablo, two former youth team players at Flamengo, joined in the throng as if they were lifelong Los Blancos supporters.

"We tried to get tickets in the LDU end but it just wasn't possible," said Pablo, who even had his shirt signed by Quito star Damian Manso. Meanwhile, observing the scene with a wry smile was Rodrigo Lara, a member of the hotel staff and a Fluminense fan: "Look how petty they are. They (Flamengo fans) have to support another team if they want to have something to celebrate," he said.

Club rivalries and the potential for schadenfreude aside, one thing is for sure: 3 July will be a memorable day for everybody involved with Fluminense. Should they manage to overturn their first-leg deficit, Thursday will be spent revelling in a historic triumph. And should they fall short, the LDU victory celebrations will have a noticeable Rubro-Negro tinge.