It took two stoppage time goals for Borussia Dortmund to beat a stubborn Málaga, and by coach Jürgen Klopp's own admission, they need to improve if they are to have any chance of reaching the final. Meanwhile, Real Madrid saw off Galatasaray in the quarters, but only after letting the Turkish side back into the game needlessly, conceding three times in 20 minutes.
Despite letting their concentration wane against Gala, Real Madrid are still the stronger of the two sides here, and will be expected to progress to the final. However, they will have to be wary of last season's Bundesliga champions, who weren't helped defensively against Málaga with the absence of their star centre-back Mats Hummels.
These sides met twice earlier in this very competition, when they were drawn together in the group stages. Dortmund managed to surprise José Mourinho's team with a victory at the Westfalenstadion, before taking an impressive 2-2 draw at the Santiago Bernabeu.
Cristiano Ronaldo. It's clear, but Ronaldo will be the best player on the field when these sides meet, and will look to exploit any room he is given on the left flank. A player with the capability to turn a game in an instant, he'll provide the major defensive headache for Dortmund.
Matchups to watch
Cristiano Ronaldo vs. Łukasz Piszczek - On that note, Ronaldo's battle with the offensively-minded Polish right-back Łukasz Piszczek will be fundamental to the outcome of the match. Against Málaga Piszczek was one of Dortmund's key attacking outlets with his running down the right flank, though he can't afford to leave any room for Ronaldo here.
The Real Madrid defence vs. Mario Götze and Marco Reus - Two of the best young players in the world this season, Mario Götze and Marco Reus have excelled in their playmaking partnership. Not only the Real Madrid back four, but also Xabi Alonso and Sami Khedira will have to try to stop the duo interchanging.
Mesut Özil vs. İlkay Gündoğan - Two young German Turks, Mesut Özil and İlkay Gündoğan will both have offensive and defensive duties to attend to in this game. Gündoğan, playing deep in the Dortmund midfield, is an excellent all-rounder, capable of both playmaking and tackling. Alongside a midfield partner (probably Sven Bender), he'll have the unenviable task of shutting down Real Madrid's advanced playmaker Mesut Özil, who himself will have to stay disciplined, trying to restrict the space in which Gündoğan can work.
Real Madrid through by two goals - Dortmund will prove to be tough opponents for Real Madrid -- as they've already shown this season. But, ultimately, los blancos should have enough of a quality and experience advantage over the young German side to take victory.