Fabio Fognini will meet Fernando Verdasco in the semi-finals of the Swedish Open after they both won in straight sets on Friday.
Spanish veteran David Ferrer – a three-time winner and this year's seventh seed – was beaten 7-5 6-2 by Caser Ruud.
Eugenie Bouchard is in position to challenge for the Ladies Championship Gstaad as the seeds tumble.
A three-time finalist at the Hall of Fame Tennis Championships, Ivo Karlovic suffered a second-round loss.
Pablo Carreno Busta and Fernando Verdasco will meet in Bastad but top seed Diego Schwartzman was knocked out on Wednesday.
Romanian Mihaela Buzarnescu thrilled her home crowd by rallying in the second set to beat Tamara Zidansek in Bucharest.
Sixth seed and Luxembourgish veteran Gilles Muller saw off Marcos Baghdatis 7-6 (7-5) 6-3 in Newport on Tuesday.
Fernando Verdasco and David Ferrer were victorious in Bastad but Benoit Paire tumbled out in Umag.
Tournament organisers have revealed there will be a five per cent increase for this year's grand slam at Flushing Meadows.
Samantha Stosur looked in impressive form at the Ladies Championship Gstaad, while home favourite Sorana Cirstea triumphed in Bucharest.