The top-seeded Nalbandian blew a 5-2 lead in the first set. But he powered up his backhand and rolled into a seventh career matchup with Ferrero on Friday.
Former No. 1 Ferrero beat seventh-seeded Marcel Granollers 6-7 (7), 6-0, 6-3 to reach his second quarterfinals in two weeks. He also made the last four last week in Brazil.
Ferrero won the last of his 11 titles in 2003, and has lost nine finals since then. But he's 3-3 against Nalbandian, who won his 10th title last month in Sydney.
Also, Franco Ferreiro beat fellow qualifier Pablo Cuevas 6-2, 6-4 to for his second match victory on the main ATP Tour.
Ferrero into Buenos Aires quarters
Luis Fabiano Leaves Sevilla For Brazil For Knee Rehabilitation
La Liga Preview: Valencia - Malaga
Ferrero into Buenos Aires quarters
