Philipp Kohlschreiber ousted second seed Marin Cilic on Friday to reach the semi-finals of the Rotterdam Open.
World number 32 Kohlschreiber defeated Cilic 3-6 6-3 6-4, denying the Croatian an opportunity to improve on the loss he suffered to Tomas Berdych in the final of the ATP 500 event in 2014.
Kohlschreiber was broken once in the first set and while Cilic gave up his serve only twice in the match, those breaks proved fatal to the world number 13's chances, coming in the eighth game of the second set and the first game of the third, ending his hopes on the indoor hard courts of the Ahoy Rotterdam.
The German will face Gael Monfils after the Frenchman shook off the challenge of Alexander Zverev in straight sets.
Monfils prevailed 7-6 (7-4) 6-3 to move through to the semis as the defeated 18-year-old German, who upset Giles Simon yesterday, put up a good fight.
The victorious Monfils punished Zverev on his second serve, winning 58 per cent of second serve return points.
Earlier, qualifier Nicolas Mahut upset eighth seed Viktor Troicki 6-2 6-1 in just one hour and 12 minutes.
The Frenchman's consistent first serve carried him into the last four - he won 88 per cent of first-service points and saved all three of the break points he faced in the match.
Mahut will face Martin Klizan for a place in the final after the Slovak came from a set down to battle past sixth seed Roberto Bautista Agut 6-7 (5-7) 7-6 (8-6) 6-0.
Spaniard Bautista Agut led 5-3 in the second and held match point on five occasions before losing the tie-break and collapsing to suffer an embarrassing bagel in the third.