5 reasons why the Real Madrid vs. Bayern Munich rivalry is so bitter

Two of the biggest clubs in the world will meet at Estadio Santiago Bernabéu for the first leg of their Champions League semi-final on Wednesday. 

Real Madrid and Bayern Munich are no strangers having battled it out over the years, not only in European competition, but also for transfer targets. 

Former Bayern President Uli Hoeness once labelled Florentino Perez's Galactico project, which saw Real acquire some of the biggest stars in the world, "a monkey circus." Harsh words from a man now in prison. 

They'll renew their rivalry for the 15th time on the biggest stage, but before they do, lets look back at some of their greatest clashes. 

5) 'The madman of the Bernabeu'

The 1976 European Cup semi-final is halted when a deranged Real Madrid supporter fan runs on the field and assaults Austrian referee Erich Linemayr and Gerd Muller, whose equalizer sent the teams back to Munich tied 1-1. 

Muller produces another seminal performance in the second leg, scoring twice to lead the Bavarians over Real 3-1 on aggregate. 

4) Juanito's criminal act 

Eleven years later the madman isn't a fan, but Real Madrid's Juanito. 

Bayern Munich dominates Real in their 1987 semi-final at the Olympiastadion, like they have so many times throughout the years. The rout is on when Lothar Matthäus commits a rash challenge on Chendo. 

Chendo reacts angrily, shoving Matthäus when Juanito arrives on the scene. 

Juanito is banned from European competition for five years for his brutal stomp. Ironically, his actions spurred Real to an improbable come from behind victory in the second leg. 

3) "We're going to score five goals against those clowns"

Claudio Pizarro's pre-match banter is par for the course in this rivalry, but Real Madrid isn't the one wearing the large shoes and red nose in their round of 16 clash in 2004.

Zinedine Zidane's goal in the second leg at the Bernabeu powers Real Madrid to a 2-1 win. 

Who's laughing now?

2) Van Bommel's offside celebration 

Real Madrid prevail 3-2 but Mark van Bommel steals the show with an incredible goal, and an offensive gesture to match. 

Because of the goal, Bayern Munich goes through 4-4 on the away goals rule, and advances to the 2007 Champions League quarterfinals. 

1) Sergio Ramos hits one into the sky 

A thrilling 3-3 semi-final comes down to penalties. Jose Mourinho is nearly unable to watch as shooter after shooter steps up to the spot. 

Sergio Ramos sails one over the bar, allowing Bastian Schweinsteiger the opportunity to end it. He does, and sends Bayern Munich to the finals.

[H/T to Samuel Luckhurst and Graham Hunter]