After an entertaining 0-0 draw at the Vicente Calderon, Real Madrid host Atletico Madrid in the Champions League quarter final second leg - and here are a few talking points before the game.
If Los Rojiblancos avoid defeat to Real Madrid on Wednesday night, it would extend their unbeaten run against them to eight games, an astonishing stat.
In terms of beating Real, Diego Simeone seems to have found a system that on derby day gets the best out of his players and provides a belief that they are in fact better than their rivals. Incredible, given the players that they face - Ronaldo, Benzema, Bale, James, Modric, Kroos, Ramos - just to name a few.
Yet, something changed in the the first leg of the Champions League quarter-final final, for the first time Real started to find more holes, more space in Atletico's half. It resulted in them having 16 shots, more than they had managed in their past two games at the Vicente Calderon combined. This will give Los Blancos and bit more encouragement.
Away to their rivals, Atletico have lost just one game in the past six meetings, winning three. What will worry Real Madrid fans is they have managed to score in five of the past six games at the Bernabeu, a total of eight goals.
How will Real Madrid cope without Modric and Bale?
Modric injured his thigh in November and had only just started playing again for Real Madrid before his most recent injury against Malaga, so they have had to deal with this for most of the campaign.
Had Modric been fit for most of the season, we perhaps wouldn't have seen such a drastic dip in form for Real Madrid during the second half of the season, a dip which saw them surrender the lead at the top of the table and get knocked out of the Copa Del Rey (to Atletico).
At times, in what is a midfield littered with talent, they lacked the Xabi Alonso figure which they failed to fill in the summer. With Sami Khedira hardly playing and Asier Illaramendi failing to establish himself, a midfield of James Rodriguez, Toni Kroos and Isco doesn't exactly offer much defensive support. They lacked the man who does the dirty work and starts the play from deep.
Gareth Bale being unavailable will be a blow for Real Madrid, regardless of the criticism he has received. He was made for games like these. Bale last season - even without a pre-season - showed the fans that he can stand up and be counted.
He won them the Copa Del Rey with an amazing solo goal, while he scored the goal that put them ahead in extra time in the Champions League final which they later went on to win. He also relieves some of the pressure on Cristiano Ronaldo, not that the Portuguese doesn't love the spotlight.
In a game like this, you need as many match winners as you can get, and Real are missing two huge ones.
Fast starters again?
Atletico managed to score in the first minute of each half in their last appearance at the Santiago Bernabeu, with Fernando Torres getting both goals in a 2-2 draw. It begs the question: How will Atletico approach this tie?
They managed to keep a clean sheet and avoid Real Madrid scoring a precious away goal, meaning if they score they don't have to endure the prospect of 120 minutes or penalties at the home of their rivals.
We know how compact and well drilled they are defensively, and they show enough character to snatch themselves a goal when necessary. They know that Real will look to dominate the game, and they will be more than willing to let that happen, especially with the emphasis being on the home side to take it to them.
They have shown in the past that they can match any opponent on their day, but you just wonder if they will attack from the early moments, try and get the first goal, then sit on their lead.
How much will the occasion affect the way they handle the tie? There's a huge difference between a Copa Del Rey last-16 tie and a Champions League quarter final.
Ancelotti or Simeone?
The mere fact that Diego Simeone has been able to go toe to toe tactically with Carlo Ancelotti shows just how talented a manager he is. He knows his side, he knows who to play and when to play them.
When you compare the two through trophies won as a manager there is no comparison, so Simeone is doing a lot with so little. I don't speak of Atletico as being underdogs anymore, they are an established team now, winning a league title and reaching a Champions League final doesn't happen to any team, especially when you have two of the best teams in the world in your league.
They show that if you invest your money in the right players, losing a superstar can build you into an even bigger side. Compare them to Spurs and how they have dealt with losing their top players, very similar to Atletico, and they are two teams in very different places.
Ancelotti is unlikely to be at Real Madrid next season, that's just the way it is. You have a manger in one dugout who the fans want out when they don't win everything every season, and in the other, a man who can do absolutely no wrong.
Fans have no sympathy for their side if they hit a bad spell, they won't encourage, they feel that when you sign for Real, you understand that you have to perform week in week out and deal with pressure.
It's your problem if you find it hard to settle in, and for a team that is the most famous club in the world, won team of the century and 10 European titles, you know that they'll love you when you're good, and criticise when you're bad. They're winners.
Expect a fierce game, played with a true derby spirit, and the theatrics that come with all that. It won't have the skills you'd find in El Clasico, but it will have entertainment.
Go back four years ago you'd say this was a no contest, nowadays you wouldn't shock anyone if you tipped Atletico Madrid to win this.
Who will win tonight? Let us know below!