Atletico Madrid have a chance in Saturday's Champions League final not only to claim their debut European crown but to deny their loathed and vastly wealthier neighbours Real Madrid a record-extending tenth.
Atletico have already outperformed this season in securing a remarkable La Liga triumph, shattering the domestic dominance of Real and Barcelona and becoming the first team other than the big two to win the Spanish title since Valencia in 2004.
They are also back competing with the continent's elite after a lengthy absence and the first showpiece between teams from the same city in the 59-year history of the European Cup is their second final after they lost out to Bayern Munich in 1974.
Real, the world's richest club by income who have splashed more than €600m on players over the past five years, are appearing in their 13th final, but the first since their last success in 2002.
Their vast outlay is proof of Real president Florentino Perez's obsession with winning what is known in Spain as "la decima" (the tenth).
After Real's La Liga campaign faltered in the final weeks of the campaign, failure in Lisbon would be a massive blow to the construction magnate's prestige.
"From the first day a player arrives at the club, he is already saying that he has come to win the 'decima'," former Real forward Predrag Mijatovic said in an interview with Marca sports daily.
"There is too much pressure being put on the players," added the Montenegrin, who scored the winner in Real's 1-0 Champions League final triumph against Juventus in 1998.
"The best way to take the sting out of this obsession is winning and then we won't be talking about the tenth anymore."
Atletico, known as "the mattress makers" after their red and white-striped shirts, and Real, who play in all-white and are nicknamed "the meringues", have met only once before in continental competition, in the European Cup semi-finals in 1958-59.
Real went through to what was their fourth consecutive final after winning a replay in Zaragoza when Ferenc Puskas scored the winner in a 2-1 success.
"There is too much pressure being put on the players"
The city neighbours have met four times this season. In La Liga, Atletico won 1-0 at Real's Bernabeu stadium and they drew 2-2 at the Calderon in the return, while in the two-legged King's Cup semi-finals Atletico were on the end of a 5-0 aggregate drubbing.
Those encounters are unlikely to have much impact on the Champions League final, with Atletico, unbeaten in Europe this term and on a high after wrapping up the La Liga title on Saturday and Real under enormous pressure to avoid what would be a humiliating reverse.
Cristiano Ronaldo, top scorer in this season's competition with a record 16 goals, believes the expectation weighing on him and his team mates can be used to their advantage.
"Since the first day we came here, we've felt that positive pressure to win the Champions League," the FIFA Ballon d'Or winner told the UEFA website.
"Real Madrid have wanted it for a long time," added the Portugal captain, a European champion with Manchester United in 2008. "It is a moment that the whole Madrid family are dreaming about - the 'decima'."
Atletico, meanwhile, are sweating on the fitness of top scorer Diego Costa, who has eight Champions League goals this term.
The Brazil-born forward, a Spain international, has been suffering with a series of muscle problems and limped out of Saturday's title decider at Barcelona along with Turkey playmaker Arda Turan.
"We will wait to see how the Diego Costa and Arda Turan injury situation evolves by the end of week," Atletico coach Diego Simeone told a news conference. "We will seek alternatives if they do not recover in time."
If Costa and Arda are sidelined, forward Adrian, who scored the opening goal at Chelsea in the semi-final second leg and attacking midfielder Raul Garcia are likely to come in.
Simeone's Real counterpart Carlo Ancelotti also has injury concerns, with forward Karim Benzema and centre back Pepe in a race to get fit.
"Right now they can't play but we have four more days until the final and we will make a decision right at the end," Ancelotti, bidding to become only the second man after Liverpool's Bob Paisley to win the European title three times as a coach, said.
Raphael Varane would replace Pepe if necessary, added the Italian, while Alvaro Morata could come in as a straight swap for Benzema at centre forward.
Real's chances were dealt a blow in the semi-final against holders Bayern when midfielder Xabi Alonso earned a booking that means he is suspended for the final.
They are likely to miss the control he gives the team and likely replacement Asier Illarramendi, who has failed to impress since joining from Real Sociedad, may be out of his depth against Atletico's experienced midfield.
Atletico have held one celebration at the Neptune fountain in central Madrid this season, partying with their delirious fans after winning La Liga for the first time in 18 years, and will be hoping to return with the European Cup.
Should they fall short, Real and their fans will flock to the nearby Cibeles fountain having finally claimed the elusive 'decima' after more than a decade of disappointment.
Watch live Champions League final television coverage Real Madrid v Atletico Madrid (Saturday 24 May, RTÉ Two and RTÉ.ie, 7pm, Republic of Ireland only).