LUXEMBOURG -- Top-seeded Caroline Wozniacki struggled to a 6-3, 7-6 (2) win over local Mandy Minella to reach the second round of the Luxembourg Open on Tuesday.
Second-seeded Sloane Stephens of the United States had an easier time, defeating 2009 champion and Swiss wild card Timea Bacsinszky 6-3, 6-3.
Two seeds fell: No. 4 Kirsten Flipkens of Belgium lost to Katarzyna Piter of Poland 6-4, 6-2, and No. 6 Mona Barthel of Germany lost to Stefanie Voegele of Switzerland 1-6, 6-4, 7-6 (3).
Third-seeded Sabine Lisicki of Germany started slowly against Croatia's Donna Vekic before she recovered to win 2-6, 6-3, 6-0.