Spain's Tommy Robredo made a second round exit to Leonardo Mayer at the Royal Guard Open in Chile.
The Argentinian, who was making his fourth straight tournament appearance, upset the second seed 3-6 7-6 (8) 6-4.
Robredo, the 2011 champion, had a first-round bye and although he won the opening set comfortably, the 91st-ranked Mayer took a tense second set before edging the decider.
Seventh-seeded Guillermo Garcia-Lopez of Spain made the last eight defeating Paolo Lorenzi of Italy 3-6 7-5 6-4 at the clay-court event in Vina Del Mar.
Top-seeded Fabio Fognini plays on Thursday against Aljaz Bedene of Slovenia in a second round match.