Madrid bars will be packed Saturday with red-striped Atletico Madrid football fans and Real Madrid rivals, all in white, drinking and yelling the night away for the first one-city Champions League final.
The two sides will not mix for the historic occasion though. The match will be a new test of a century-old rivalry between the two sides in the Spanish capital.
Some 1,250 police will be on duty to prevent clashes.
"It is going to be a tense atmosphere. People will be very nervous," said Marcos Vinagre, a 32-year-old Atletico fan who works as a porter in Madrid.
He thanks his father for making him an Atletico fan even though most of his friends support Real.
"The fans are going to spend the night each on their own turf with their own people," said Alejandro Lora, 64, president of an association of Real Madrid fan clubs.
"There's a lot of excitement. They have been rivals since the very beginning."
Shop windows dummies are dressed in the rival team shirts and on public squares hang giant posters of each team's colours -- red and white for the Atletico "Colchoneros" and meringue-white for the Real "Merengue".
Real and Atletico will dispute the final in Lisbon. If Real win it will be their 10th European title. For Atletico it would be a first.
Local authorities had planned to screen the match on Madrid's Puerta del Sol square. They changed their minds after security warnings.
Instead, separate giant screens will go up at Real's Bernabeu stadium in the posh north and Atletico's Vicente Calderon in the poorer southwest.
Police in Spain's Extremadura region, on the road to Portugal, say they will try to keep busloads of rival fans apart at service stops on the way.
"Naturally in Lisbon they may cross paths," Lora said. "But I don't think there will be major problems."
- Superiority complex -
The city rivalry had eased in recent decades as Real fans, flush with silverware, went after their bigger rivals Barcelona.
"It was much more intense in the sixties when Atletico was in a stronger position. There was lots of tension," said Alfredo Relano, editor of Madrid sports daily AS.
"Now suddenly we have this gift of a European final which has never been played between two teams from the same city. It could again become what it was in the sixties."
With 32 home league titles and nine European crowns, Real's fans can afford a condescending attitude.
"We don't have the same feeling of rivalry that Atletico have towards us," said Lora. "I understand their feeling. It is normal since Real Madrid has had more success."
But the mood has changed since Atletico beat Real in the 2013 Spanish cup final and last Saturday sealed their first league title in 18 years.
"We may feel inferior in terms of history, but today I think we are just as good" as Real, said Vinagre.
"Each year we thought the next year would be better -- until 18 years had passed."
- Guapa, lista, antimadridista -
Rivalry between Real, founded in 1902, and Atletico, born a year later, has long been seen as a clash of rich and poor.
Relano reckons this image is out of date, even though Real Madrid's fans still have a more genteel image and Atletico's a rowdy one.
Real players and even their opponents can expect to hear respectful applause in the Bernabeu. The Calderon bubbles with abuse and chants of "Atleti, oh-eh, oh-eh."
Kiosks near the Calderon sell women's pink scarves with the slogan: "Mummy made me pretty, smart and anti-Real Madrid". It rhymes in Spanish: "Guapa, lista, antimadridista."
"There are insults, but relations are not violent," said Relano.
Both sets of fans are scattered around the city and rub shoulders at work.
After a big win, the Colchoneros rush to party around a statue of the Roman god Neptune in the centre of town.
The Merengue celebrate just up the road around a statue of the Greek goddess Cybele.
Still, for Spanish football's image, Relano agreed it was better to avoid screening the match on Sol, "just in case".
Media quoted government officials worrying about the "atmosphere of high rivalry."
"In the end most people will join in the party," said Vinagre, however.
"One lot to celebrate the victory and the others to drown their sorrows -- and to celebrate even having played in a Champions League final."