In total, Real Madrid and Dortmund have faced each other 14 times, with the result being six wins for Los Blancos, five draws and three wins for Dortmund.
The first meeting came in the 1997/98 season, in the Champions League semi-finals. Madrid were looking to take a step towards their seventh title, after a 32-year drought. The first leg, played at the Bernabeu, went down in history, and not just because of the result.
A few minutes before kick-off, one of the goals collapsed. A fall from a group of fans in the area caused the cables holding it in place to be dragged down and it collapsed. The club had to take improvised measures to allow the match to go ahead.
The team's delegate, Agustin Herrerin, went to the Ciudad Deportiva on a motorbike and found a new goal, which was moved to the Bernabeu. The match resumed an hour and a half later.
On the pitch, Real Madrid responded in style and won 2-0 with goals from Fernando Morientes and Christian Karembeu. The second leg ended goalless and Madrid would go on to win the Champions League in the final in Amsterdam against Juventus.
They would later meet in 2002/03 in the group stage, with the clashes ending 2-1 to the hosts in Madrid and 1-1 in Dortmund. They would not meet again until 2012/13.
In that season, Real Madrid and Borussia Dortmund met four times. In the group stage, it was 2-1 to the home side in Germany and 2-2 in Spain, and then came the semi-finals.
Dortmund, who had just eliminated Malaga in the quarter-finals in stoppage time and with controversy, thrashed Madrid 4-1 in a match that is remembered best for Robert Lewandowski's four goals in 58 minutes. Cristiano Ronaldo scored Madrid's goal.
Mourinho's side played a great second leg at the Bernabeu but lacked the killer instinct to turn things around. Karim Benzema and Sergio Ramos scored in the last 10 minutes, but their side couldn't find the third goal they needed.
Dortmund would play against Bayern Munich at Wembley and ended up narrowly losing with their rivals scoring a late winner.
The last time the two teams met in the knockout stages was in 2013/14. It was the quarter-finals of a season that ended with Real claiming their tenth Champions League in the Lisbon final against Atletico Madrid.
Real thrashed Dortmund at the Bernabeu with goals from Gareth Bale, Isco and Cristiano Ronaldo. In front of the yellow wall, Dortmund tried to mount a comeback but fell a goal short despite Marco Reus' brace.
The last four meetings have been in the group stage. In 2016/17 they drew 2-2 and in 2017-2018 it was back-to-back wins for Blancos, 3-1 to the visitors in Dortmund and 3-2 at the Bernabeu.