Sanchez does a double
The idea of players crossing the city was not new, even then.
Santiago Bernabeu, the legendary Blancos president who gave his name to the iconic stadium they play in to this day, guested with Atletico in the 1920s.
Real loaned Atletico forward Ramon Grosso in 1963-64 to help fight off relegation, while Mexico's Hugo Sanchez actually scored for both teams in La Liga derbies during the 1980s.
Not so friendly
That is not to say it's always been friendly. While ‘El Clasico' with Barcelona is arguably La Liga's biggest game internationally, for many at Real the derby remains the most special.
"The team we wanted to beat, at all costs, was the neighbours," Blancos legend and all-time great Alfredo Di Stefano recalled.
"Losing meant our fans had to suffer jokes from the next day in the office, the bar and the street."
Wanda the venue
Over the years La Liga has provided 163 opportunities for such ribbing. Real have 86 victories, Atletico 39 wins, with 38 draws, including the most recent games at both the Bernabeu and Wanda Metropolitano stadiums.
Former Real Madrid winger and the club's current honorary president Paco Gento holds the all-time record for appearances in the fixture with 29, while Atletico's record appearance maker in the fixture is also the club's all-time appearance record holder: Adelardo Rodriguez with 27.
Ramos on top
Of current players Blancos captain Sergio Ramos (24) and Atletico midfielder Koke (13) top the lists.
Di Stefano and 1980s striker Santillana have the most LaLiga goals in the fixture for Real (13), while 1940s teammates Paco Campos and Adrian Escudero share the record for Atletico with nine each.
Cup competitions have recently taken the rivalry to new heights at home and abroad. Atletico beat Real in the 2013 Copa del Rey final.
Real came out on top in the 2014 and 2016 Champions League deciders, while Diego Simeone's side beat their neighbours most recently in the 2018 UEFA Super Cup.
Adding extra spice this season are Real Madrid goalkeeper Thibaut Courtois and coach Santiago Solari, who made their first appearances in LaLiga for Atleti across town.
Argentinian Solari has an enviable unbeaten record in La Liga derbies... on both sides of the divide.
Saul in focus
Going the other way, Atletico midfielder Saul Niguez and defenders Juanfran Torres and Filipe Luis all spent time in Madrid's youth system as teenagers.
Saul, who is returning from injury, is expected to play a key role as the stage is set for an exciting derby.