Two-time defending champion Caroline Wozniacki overcame Urszula Radwanska of Poland 7-6 (4), 6-2 on Tuesday to reach the second round of the e-Boks Open.
The 21-year old Dane was down a break in the first set before rallying to force the tiebreaker. She then broke three times in the second to clinch the victory in 2 hours, 5 minutes.
Wozniacki, ranked sixth in the world, will next play Pauline Parmentier of France, who ousted Anna Chakvetadze of Russia 7-5, 6-1.
Fourth-seeded Monica Niculescu of Romania also advanced, beating Valeria Savinykh of Russia 6-2, 6-2, while No. 5 Kaia Kanepi of Estonia ousted Anastasia Rodionova of Australia 6-3, 6-4.
Wild-card Malou Ejdesgaard of Denmark was routed out of the tournament, ousted by France's Alize Cornet, who won the match 6-0, 6-0.
In other action on the indoor hardcourt, Australia's Johanna Konta beat seventh-seeded Ksenia Pervak of Kazakhstan, 6-3, 1-0, after Pervak retired, and fifth-seeded Kaia Kanepi of Estonia defeated Anastasia Rodionova of Australia. Mona Barthel of Germany, seeded sixth, won over Sweden's Johanna Larsson, while second-seeded Angelique Kerber of Germany beat Stephanie Foretz Gacon of France.
Croatia's Petra Martic beat Germany's Annika Beck, Britain's Anne Keothavong won against Hungary's Melinda Czink, and Austria's Patricia Mayr-Achleitner ousted eighth-seeded Sofia Arvidsson of Sweden.