Thomaz Bellucci's defense of the Swiss Open title ended in the first round on Tuesday when he lost to Federico Delbonis, who beat Roger Federer in Germany last week.
Delbonis, an Argentine, won 7-5, 7-6 (2) against Bellucci, a Brazilian, who also took the clay-court title at Swiss ski resort Gstaad in 2009.
Delbonis will continue rising in the rankings after victory over Federer in the Hamburg semifinals helped him climb from No. 114 to 65.
Federer is top-seeded this week and has a second-round match scheduled on Thursday.
Four Spaniards had first-round wins on Tuesday.
Eighth-seeded Roberto Bautista eased past Henri Laaksonen of Switzerland, 6-2, 6-3; Daniel Gimeno-Traver beat Kenny De Schepper of France, 6-4, 6-4; Guillermo Garcia-Lopez beat Adrian Ungur of Romania, 6-4, 6-7 (2), 6-1; and Pablo Andujar eliminated Victor Crivoi of Romania, 6-1, 6-2.