SYDNEY (AP) -- Samantha Stosur overcame some home-crowd jitters to beat Lucie Safarova 7-6 (3), 5-7, 6-3 Monday in the first round of the Sydney International, and Caroline Wozniacki's Australian Open preparations took a hit when she was forced to withdraw with a wrist injury.

Stosur saved three break points to take a 3-2 lead in the third set before breaking Safarova again when the Czech player double-faulted on back-to-back points.

''It was relatively important win,'' the Australian said. ''It was good to step up and win the match after what happened last week, and I am very happy with it.''

Stosur, who won the 2011 U.S. Open, has never been past the fourth round at the Australian Open. And she has struggled at other tournaments Down Under, too. Last week at the Brisbane International, Stosur lost to Varvara Lepchenko 4-6, 6-4, 7-5 in the first round after leading 5-1 in the third set.

Stosur will next play Barbora Zahlavova Strycova of the Czech Republic in the second round after Wozniacki withdrew from their match with a left wrist injury. The fourth-seeded Dane trailed 6-4, 1-1 when she walked to the net and said she couldn't continue.

Wozniacki was coming off a hard-fought loss to Venus Williams in the final of the ASB Classic in Auckland, New Zealand, on Saturday, and the injury throws into doubt her fitness for the Australian Open.

In other matches, third-seeded Agnieszka Radwanska of Poland beat Alize Cornet of France 6-3, 6-2 and fifth-seeded Angelique Kerber of Germany defeated Lesia Tsurenko of Ukraine 1-6, 6-4, 6-3.

Sixth-seeded Ekaterina Makarova of Russia, seventh-seeded Dominika Cibulkova of Slovakia and Garbine Muguruza of Spain also won while eighth-seeded Flavia Pennetta of Italy lost to Bulgarian qualifier Tsvetana Pironkova 6-3, 7-6 (4).

On the men's side, fifth-seeded Leonardo Mayer beat Benjamin Becker 7-6 (3), 6-2 and sixth-seeded Pablo Cuevas defeated Nicolas Almagro 7-6 (5), 6-4.

At the Hobart International tournament in Tasmania, top-seeded Casey Dellacqua of Australia beat Lauren Davis of the United States 6-4, 1-6, 6-4.

Also, third-seeded Camila Giorgi of Italy overcame 23 double-faults to beat Australian wild-card entry Storm Sanders 5-7, 6-1, 7-6 (6), and second-seeded Zarina Diyas of Kazakhstan defeated Silvia Soler-Espinosa 6-3, 6-4.

Adrian Mannarino of France beat Federico Delbonis 6-1, 6-1 at the Heineken Open in Auckland in the first match of a draw gutted by the late withdrawals of defending champion John Isner, top-seeded David Ferrer and Gael Monfils.