Top-seeded Janko Tipsarevic of Serbia defeated Grega Zemlja of Slovenia 6-4, 6-2 to reach the quarterfinals of the BMW Open on Thursday.
Tipsarevic is bidding for his second title of the year after winning the Chennai Open at India in January. He will face Daniel Brands of Germany, who beat Gael Monfils of France 6-3, 3-6, 6-0.
Third-seeded Tommy Haas overcame Ernests Gulbis 6-4, 6-7 (3), 6-2 to set up a quarterfinal with Florian Mayer. Sixth-seeded Mayer beat Marinko Matosevic 2-6, 6-4, 6-2.
The 35-year-old Haas, a finalist in 2000, is bidding to win the title for the first time in his 10th appearance.