Former world number one Andy Murray recorded a straight-sets win for just the second time since August at the European Open in Antwerp.
Richard Gasquet lost for just the second time in nine career meetings with Benoit Paire in an-all French clash in Metz.
After dropping down to the Challenger Tour for the second time this season, Jo-Wilfried Tsonga hit the ground running in Metz.
Daniil Medvedev was a set down against Novak Djokovic, but he rallied to stunning 3-6 6-3 6-3 semi-final victory in Cincinnati on Saturday.
Daniil Medvedev and Novak Djokovic will meet in the semi-finals, while David Goffin and Richard Gasquet are set to clash.
Marin Cilic and Andy Murray both exited the ATP Masters 1000 tournament in Cincinnati on Monday.
Andy Murray was beaten by Richard Gasquet in straight sets in his first singles match since undergoing hip resurfacing surgery.
Three-time grand slam champion Stan Wawrinka outclassed Grigor Dimitrov in straight sets on day one of the ATP 1000 event in Montreal.
Italian qualifier Salvatore Caruso ripped up the script in Umag, beating world number 14 Borna Coric to reach the quarter-finals.
Jo-Wilfried Tsonga was unable to pull off a third consecutive win over Roger Federer as the top seed reached the last eight in Halle.