Buenos Aires - Top-seeded David Ferrer defeated fellow Spaniard Albert Ramos 6-1, 6-2 on Friday to reach the semi-finals of the Copa Claro tournament in the Argentine capital.
Ferrer, the two-time defending champion in Buenos Aires, is aiming to win his 21st ATP tournament.
Ferrer will next face fellow Spaniard Nicolas Almagro, the fourth seed, who defeated Jeremy Chardy of France 7-6 (7), 6-3 in another quarter-final match.
Second-seeded Fabio Fognini of Italy and third-seeded Tommy Robredo of Spain also won to set up a semi-final matchup.
Fognini, who won the ATP event last week in Chile, advanced by defeating Pablo Andujar of Spain 6-4, 6-3. Robredo advanced when Robin Haase of the Netherlands retired with a back injury while trailing 6-1, 2-0.
World No 1 Rafael Nadal pulled out of the tournament with a back injury of his own, but he will play next week in the Rio Open in Rio de Janeiro.