SYDNEY -- Only days after her New Year's Eve engagement to golfer Rory McIlroy, Caroline Wozniacki opened her 2014 season on Monday with a 3-6, 6-2, 6-4 win over Julia Goerges of Germany in the first round of the Sydney International.
Wozniacki withdrew from the Brisbane International last week after hurting her right shoulder in practice and struggled early against Goerges, who was replacing the injured Sloane Stephens in the draw.
Fifth-seeded Angelique Kerber of Germany beat Dominika Cibulkova of Slovakia 7-6 (5), 7-5 to move into the second round at the Sydney International, one of the last warm-up tournaments for the Australian Open.
On the comeback from a long layoff with a knee injury, Mattek-Sands had a first-round loss in Brisbane last week and went through three rounds of qualifying for Sydney. She next faces defending champion and No. 1-seeded Agnieszka Radwanska.
"She reads the ball so early so it's going to be a great battle," Mattek-Sands said of her second-round match. "But I'm looking forward to it. This is why you train -- it's to play the best players in the world. So why not play the No. 1 seed?"
The Hobart International had another injury setback Monday when fifth-seeded Flavia Pennetta withdrew citing a wrist injury, a day after Venus Williams pulled out following her run to the final at the ASB Classic in Auckland, New Zealand.
Top-seeded Samantha Stosur needed five match points before beating American qualifier Madison Brengle of the United States 6-7 (4), 6-1, 7-6 (5) in a match interrupted twice by rain, eighth-seeded Bojana Jovanovski of Serbia had a 7-5, 6-3 win over Annika Beck of Germany, and Yanina Wickmayer of Belgium advanced when Laura Robson retired in the second set. Robson won the first set 6-4, but was down a break at 2-0 when she retired in the second.
In other first-round matches in Hobart, Spanish qualifier Estrella Cabeza Candela beat Karin Knapp of Italy 7-5, 6-4, Australian wild-card entry Casey Dellacqua beat Belgian qualifier Alison Van Uytvanck 6-4, 6-4 and Zhang Shuai had a 6-3, 6-1 win in an all-Chinese match against Zheng Jie.
Sock, who won the 2011 U.S. Open mixed doubles title with Melanie Oudin, served 11 aces in the match.