World number five Alexander Zverev advanced to the last four at the Geneva Open with a three-set win over Hugo Dellien on Thursday.
Zverev, who has been drawn in the same quarter as Novak Djokovic at the French Open, came out a 7-5 3-6 6-3 winner in Switzerland.
The top seed was taken the distance by Bolivian star Dellien but was pleased with the nature of his display in the quarter-finals.
"I played very aggressive in the important moments, very, very aggressive," said Zverev. "Also in break points down, I played very aggressive.
"This is finally something I was looking for in the last few weeks, months, and today I think I showed it."
Zverev will face Federico Delbonis in the semi-finals. Delbonis had knocked out defending champion Marton Fucsovics in the last 16 and then defeated Albert Ramos Vinolas.
Radu Albot and Nicolas Jarry, both straight-set winners, make up the other semi-final.
At the Lyon Open, Nikoloz Basilashvili downed Jo-Wilfried Tsonga 6-4 6-4, but second seed Roberto Bautista Agut was beaten Taylor Fritz.
There were contrasting results for the young Canadian stars in action, too.
Felix Auger Aliassime beat Steve Johnson, but Denis Shapovalov lost to Benoit Paire.