Malaga remain optimistic they can overturn a 3-2 deficit against in-form Real Madrid this week and prevent a much-anticipated Copa del Rey quarter-final showdown between Jose Mourinho\'s holders and their arch rivals Barcelona. Malaga looked set to cause a huge upset in last week\'s round of 16 first leg at the Bernabeu as they raced into a 2-0 lead after half an hour and still held that advantage with just over 20 minutes to go. However, Madrid turned the match on its head with three goals in 10 minutes from Sami Khedira, Gonzalo Higuain and Karim Benzema and they will attempt to finish the job in tomorrow night\'s return leg at La Rosaleda. Mourinho\'s men have won 20 of their last 21 matches in all competitions but Malaga are not ready to give up without a fight. Captain Jesus Gamez said: \"It\'s difficult but you need to believe. We\'ve seen the queues of fans and we know they are going to be with us. If we can go 2-0 up at the Bernabeu, we can do it.\" His fellow defender Weligton added on his club\'s website: \"The cup tie is still open, something that not every team can say, so we\'re happy for that and it will be nice to face them at our ground.\" Madrid go into the match having thrashed Granada 5-1 at the weekend but, while confidence will be soaring at the league leaders, midfielder Jose Callejon knows they cannot be complacent heading into tomorrow\'s match. \"We\'re going there knowing that they are going to make things very difficult for us, but our objective is to get through,\" he said. If Madrid do progress then it is almost certain they will face Barca in the last eight with a Pep Guardiola\'s side holding a 4-0 advantage over Osasuna from their first leg match. The reigning European champions play the return leg of that match in Pamplona on Thursday, where Barcelona will look to recover from the disappointment of conceding a late equaliser in last night\'s derby with Espanyol, a result that left them five points adrift of Madrid at the top of the league standings. Elsewhere, three lower league sides will hope to defend first-leg leads against top-flight opposition and continue their cup adventures. Third tier Mirandes, who knocked out Villarreal in the previous round, look to be in the strongest position as they boast a 2-0 advantage over Racing Santander ahead of tomorrow\'s return trip to Cantabria. Also, Segunda Division sides Alcorcon - who famously knocked out Real Madrid two seasons ago - and Cordoba both hold 2-1 leads over Levante and Espanyol respectively after their home legs. Another third tier team Albacete, conquerors of Atletico Madrid in the last 32, travel to Athletic Bilbao having held the 23-time cup winners 0-0 at home. In the two other all-Primera Division ties, Valencia go to Sevilla boasting a narrow 1-0 lead while Real Sociedad are 2-0 up against Real Mallorca.