World number 44 Gilles Muller pulled off a shock by beating top seed David Ferrer in the Rosmalen Grass Court Championships quarter-finals on Friday.
Muller came from behind after dropping the opener, triumphing 4-6 6-4 7-6 (7-5) to make it into the last-four of the Dutch event.
The Luxembourger's next opponent will be Ivo Karlovic, who breezed into the semi-finals, the big-serving Croatian beating Adrian Mannarino 6-3 6-4.
Bernard Tomic also bowed out when defending champion Nicolas Mahut fought back to beat the second seed from Australia 6-7 (5-7) 6-4 6-2.
Mahut is aiming to win the grass-court event for the third time in four years and is just two victories away from another triumph after saving three of four break points, with Tomic failing to hold serve on four occasions.
The Frenchman will now face fifth seed Sam Querrey after the American eased past his compatriot Stefan Kozlov 6-3 6-0.