Sao Paulo - Three-time Brazil Open champion Nicolas Almagro defeated second-seeded Tommy Robredo 6-3, 7-6 (1) in the tournament's second round on Wednesday.
Almagro served 10 aces and had no double faults in the match between Spaniards at the clay-court tournament in Sao Paulo.
The unseeded Almagro won the tournament in 2008, 2011 and 2012. Robredo, ranked 17th in the world, won the title in Brazil in 2009.
In other second-round matches, fourth-seeded Leonardo Mayer of Argentina defeated Spaniard Albert Ramos-Vinolas 6-4, 3-6, 6-1, while lucky loser Facundo Bagnis of Argentina, who beat defending champion Federico Delbonis in the first round, retired while trailing in the first set 5-1 to fifth-seeded Pablo Cuevas of Uruguay.
Cuevas will play Almagro in the quarter-finals.