Ferrer, ranked fifth in the world, downed Facundo Bagnis 6-3, 6-4 in 77 minutes to set up a match with Fernando Gonzalez.
Gonzalez, who was given a wild-card berth in the tournament, outlasted Albert Ramos 7-6 (8-6), 7-6 (7-5) in their second-round meeting.
Fourth-seeded Kei Nishikori rallied to reach the quarterfinals with a 3-6, 7-5, 6-1 decision over Victor Hanescu and Stanislas Wawrinka survived against Benoit Paire 6-3, 5-7, 6-2.
Nishikori and Wawrinka will duel in the quarterfinals.
The second round will conclude Thursday with No. 2 seed and defending champion Nicolas Almagro taking on Federico Delbonis in the feature attraction. Almagro won the championship in Sao Paulo last week.