SANTIAGO, Chile, Feb. 3 (UPI) --
Horacio Zeballos, playing in his first tournament of the year, surprised top-seeded David Nalbandian in the second round Thursday at the Movistar Open.
Zeballos fired eight aces to defeat Nalbandian 6-2, 7-5 and earned a quarterfinal berth against Potito Starace. Zeballos reached the quarterfinals in just three tournaments last year.
Starace advanced with a 6-4, 6-1 decision over Pablo Andujar.
In other second-round action, Juan Ignacio Chela won over Caio Zampieri 6-2, 6-3 and Santiago Giraldo fought off Igor Andreev 7-6 (9-7), 4-6, 6-2.
Chela will face Giraldo in the quarterfinals. Nalbandian's exit leaves Thomaz Bellucci as the top seed remaining at No. 3. Bellucci will face Fabio Fognini Friday in the quarterfinals.
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