Two-time defending champion Nicolas Almagro was a hard-fought second-round winner Thursday at the clay-court Brasil Open.
The second-seeded world No. 11 Almagro fired 18 aces in holding off Chilean qualifier Paul Capdeville 6-4, 6-7 (3-7), 6-2 on Day 4 in Sao Paulo.
The three-time Brasil Open champ Almagro beat Italian Filippo Volandri in last year's finale here and also captured this event in Costa do Sauipe in 2008 and 2011.
Almagro's quarterfinal opponent on Friday will be oft-injured former top-five star and former Wimbledon runner-up David Nalbandian, who cruised past fellow Argentine Guido Pella, 6-4, 6-2.
A series of upsets came when Italian Simone Bolelli took out third-seeded Argentine Juan Monaco 7-5, 6-2; Volandri upended fifth-seeded Brazilian Thomaz Bellucci 6-3, 6-2; Albert Montanes erased seventh-seeded fellow Spaniard Pablo Andujar 7-5, 6-2; and Argentine Carlos Berlocq doused eighth- seeded Spaniard Albert Ramos 7-6 (9-7), 6-4. Bellucci was a Brasil Open runner-up in 2009.
Montanes will meet Bolelli in the round of eight.
The 2013 Brasil Open titlist will earn $82,300.