Tournament No. 1 seed Diego Schwartzman crashed out of the Swedish Open on Wednesday after a 6-7 (8), 3-6 defeat to Simone Bolelli.
Schwartzman's best result this year was winning his Rio Open in February, but his form has drifted since, eventually seeing him eliminated at the second round of Wimbledon earlier this month.
Elsewhere, Pablo Carreno Busta enjoyed better luck and advanced to the last eight of the competition after a 6-4, 6-4 victory over Thiago Monteiro.
Carreno, who was eliminated at the first round in this year's Wimbledon, won 78 percent of points on his first serve in his match against Monteiro.
Carreno's countryman Fernando Verdasco also cruised to victory over Pedro Sousa 6-3, 6-2.
In the other match of the day, Henri Laaksonen beat Matteo Berrettini 6-2, 6-2.