Tomas Berdych let a one-set lead slip as he suffered a quarter-final exit at the Stuttgart Open, while Alexander Zverev and Marin Cilic made the last four at the Rosmalen Grass Court Championships.
Featuring in his first tournament since splitting from coach Goran Ivanisevic, third seed Berdych fell to a 6-7 (4-7) 6-3 6-4 defeat to Feliciano Lopez.
Mischa Zverev awaits Lopez in the semi-finals after the German beat Tommy Haas - Roger Federer's conqueror in the second round - in straight sets, 6-4 6-4.
Lucas Pouille was given a run for his money by Philipp Kohlschreiber before battling to a 6-4 2-6 6-3 win and will now go head to head with Benoit Paire in the final four.
Alexander Zverev faced minimal trouble in dispatching Julien Benneteau in the Netherlands, a 6-0 6-4 triumph sending him into the semis in under 57 minutes.
Benneteau failed to work a single break point against the promising star, who produced an utterly dominant display to set up a clash with Gilles Muller, a 6-3 3-6 6-4 winner against Aljaz Bedene.
Cilic saw off Vasek Pospisil 6-3 7-5 in comfortable fashion and will take on fellow Croatian Ivo Karlovic for a place in the final.