Barcelona have been drawn at home to fellow La Liga side Leganes in the last 16 of the Copa del Rey, while Real Madrid will visit second division Real Zaragoza.
Barca and Real are level on points at the top of La Liga. Leganes are 19th in the table while Zaragoza, who were relegated from the top flight in 2013, are fourth in Spain's second tier.
Cup holders Valencia will play away to third division Cultural Leonesa, who caused one of the biggest shocks in the competition's history by knocking out Atletico Madrid yesterday.
Thirty times winners Barca had an uncomfortable last-32 game at third tier Ibiza but eventually came from behind to win 2-1. Real meanwhile beat Unionistas de Salamanca, also of the third division, 3-1.
The matches will be played on Jan. 29.