Kohlschreiber needed to finish a second-round match, which was suspended by rain Wednesday, before moving to the quarterfinals. He, Filippo Volandri and third-seeded Robin Haase all ended up taking a pair of matches Thursday.
Kohlschreiber was behind Attila Balazs 0-3 in the first set of his second-round when the rain hit Wednesday. He lost just two games after play resumed Thursday and won 6-4, 6-1. He then took on Lukas Rosol and won 71 percent of the points on serve in a 6-4, 2-6, 6-4 quarterfinal win.
Haase opened his day with a 6-4, 3-6, 6-2 win over Philipp Oswald and defeated Wayne Odesnik 6-2, 6-4. He was on the court about 3 hours Thursday.
Volandri ousted fourth-seeded Albert Ramos 6-4, 6-4 in the second round and won at the same score over Rogerio Dutra Silva.
The fourth quarterfinal was between players who won second-round matches Tuesday. Fifth-seeded Martin Klizan dominated the third set for a 1-6, 7-5, 6-1 decision over Simone Bolelli. Klizan lost 10 points over the final set.
Kohlschreiber goes against Volandri and Haase is paired against Klizan in the semifinals.