Sixth-seeded Alexandr Dolgopolov of Ukraine was knocked out of the first round of the Royal Guard Open on Tuesday, losing to Daniel Gimeno-Traver of Spain 7-6 (4), 3-6, 7-5.
In another match featuring a seeded player, No. 8 Federico Delbonis of Argentina defeated Uruguay's Pablo Cuevas 6-3, 6-4 to reach the second round.
The top four seeded players, who received byes into the second round, are Fabio Fognini (1) of Italy and three Spaniards - Tommy Robredo (2), Nicolas Almagro (3) and Marcel Granollers (4).
Others reaching the second round on Tuesday included Aljaz Bedene, Paolo Lorenzi, Pablo Carreno Busta, Martin Alund, Daniel Taro, and Santiago Giraldo.
The tournament kicks off four weeks of play in clay-court events around Latin America.
Rafael Nadal has skipped the event after playing at Vina Del Mar a year ago, but is expected to play next week in Buenos Aires.