Ferrer, the event's top seed, was a 6-3, 6-4 winner over fellow Spaniard Pablo Andujar while Almagro, the fifth seed, topped Argentina's Eduardo Schwank 6-3, 6-4.

No. 2 seed Juan Monaco of Argentina beat Spaniard Guillermo Garcia-Lopez 6-4, 6-4 and seventh-seeded Fernando Verdasco, also from Spain, ousted Germany's Mischa Zverev 6-4 6-2.

Russian Evgeny Korolev downed Spain's Daniel Gimeno-Traver 6-7 (8-10) 7-6 (7-2) 6-3 and Robin Haase of Netherlands overcame former World No. 1 Marat Safin of Russia 2-6 7-6 (11-9) 6-4.

Friday's quarterfinals pit Ferrer against Verdasco, the 2004 Valencia champion; Monaco against Almagro; No. 3 seed Tommy Robredo against eighth-seeded Italian Potito Starace; and Korolev vs. Haase.

The eventual champion will earn a paycheck of $93,000.