Cristiano Ronaldo's header in the 14th minute gave Los Blancos the lead in the Copa del Rey final. Then, the predictability of this fixture was turned on its head.
First, Diego Costa—there's more to come on him—leveled the score in the 35th minute.
The match went into extra time when central defender Miranda headed home the winner to clinch the cup for Diego Simeone's men and turn Madrid red and white.
There was a shift in mentality that night.
Atleti hadn't beaten their city rivals since 1999, and even though Madrid fans point out that it took more than 90 minutes, the win evidently inspired belief in a generation of Atletico fans who'd convinced themselves they'd never beat Madrid again.
They didn't wait as long for their next win.
Angel di Maria lazily lost possession in his own half after 11 minutes on Saturday evening in the Spanish capital. Koke and Diego Costa did the rest.
Koke produced his sixth assist of the La Liga season, as he slid through Costa to score his eighth goal of the campaign. It would prove the only goal of the night.
The win continues Atleti's perfect start, seven wins out of seven, and keeps them level with Barcelona on 21 points at the top of Spain's Primera Division.
Five points back, in third position, are the summer's big spenders: Real Madrid.
There is a lot to be said about the work that Simeone has undertook at the Vicente Calderon—especially when you consider he's yet to be in the job for two full years.
Easy on the eye they're not, but you find yourself wanting to watch them.
Built on consistency and solidness, "El Cholo" first moulded a tight defence. Thibaut Courtois, fantastic in goal, stands behind Juanfran, Miranda, Diego Godin and Filipe Luis, who are arguably La Liga's best back four at the moment.
Radamel Falcao's summer departure has arguably helped them evolve too. Costa has been excellent, Koke's industry, technique and versatility wouldn't be out of place at any side in world football and the likes of David Villa and Arda Turan offer great support.
It's a stability and functionalism which Carlo Ancelotti is struggling to find on the other half of town. He's admitted as much himself:
Luka Modric, arguably one of Madrid's most impressive performers this season, was dropped for the derby, as the Italian manager still seeks the balance that he feels is needed across the midfield.
Karim Benzema hasn't scored since Week 2 in the league, and the Madrid fans are growing restless with his lack of goals. Injuries and fitness problems with Xabi Alonso, Marcelo, Asier Illarramendi and Gareth Bale haven't helped.
With the changes that took place over the summer—including Isco and Bale's arrivals and Mesut Ozil's departure—there was always going to be a bedding-in period for a new-look Madrid side, but has this allowed Atleti to creep ahead?
And while seven games is not a season and the white side of the city will still be favourites to finish highest, Atleti are continuing to close the gap at an alarming speed.
Last year, they fell short over the final few months. Could things be different this time round?