File photo: Real Madrid's Pepe (C) is challenged by Barcelona's David Villa (L) and Sergio Busquets during their Spanish first division soccer match at Santiago Bernabeu stadium in Madrid, April 16, 2011. (Photo: Reuters)
Madrid leads Malaga 3-2 after the first leg and Barcelona is ahead 4-0 after routing Osasuna. Both will travel away from home for the second legs.
If both teams hold on to their leads, they will meet in a two-legged series in the next round later this month. That would make it nine matches against each other in the last nine months.
Madrid is waiting to find out whether Karim Benzema will be fit to play after the France striker hurt his right calf in Madrid's 5-1 league win against Granada on Saturday. Benzema has scored three goals in his last two games.
Ballon d'Or candidate Cristiano Ronaldo and coach Jose Mourinho did not travel to FIFA's award gala in Zurich on Monday because of Madrid's game a day later.
Madrid will be buoyed by Barcelona's slip-up at Espanyol on Sunday, when the Spanish champions allowed a late equalizer for a 1-1 draw that allowed Madrid to stretch its league lead to five points.
"Now they'll start talking about the end of a cycle," Barcelona president Sandro Rossel said following Barcelona's draw.
Barcelona's big lead may prove important as the club has struggled in away games this season, picking up just 13 of a possible 24 points from eight league games on the road.
Barcelona defender Gerard Pique was already looking ahead to another possible 'clasico,' with Madrid's only win in the last 12 meetings between the two clubs coming in the Copa del Rey final last season.
"The quarterfinals against Madrid would be a very emotional thing," Pique told El Mundo Deportivo newspaper.
Also, lower-tier clubs Mirandes and Alcorcon hold leads for their away legs, while Valencia has a slim 1-0 advantage traveling to Sevilla on Wednesday.
Third-division side Mirandes will look to continue its Copa run as it holds a 2-0 advantage over Racing Santander, while Alcorcon — which eliminated Madrid in 2009 — leads upstart Levante 2-1 going into Wednesday's game in Valencia.
Athletic Bilbao welcomes lower-tier Albacete after a scoreless draw while fellow Basque club Real Sociedad goes to Mallorca with a 2-0 advantage. Espanyol has the edge against Cordoba after a 2-1 victory at the second division club.
(For more sports news and updates, follow Ahram Online Sports on Twitter: @AO_Sports).
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