Caroline Wozniacki has exited 6-3, 6-3 to Dominika Cibulkova in the first round of Sydney.
Wozniacki made 10 winners and 14 unforced errors compared to 30 and 33 for her opponent.
"It's the first tournament of the year," said Wozniacki, who played exhibitions in Bangkok and Hong Kong before Sydney. "There were a few positive things in there that I can take out of it, and then I just need to work on the rest. But I'm confident that for Melbourne I'll be okay."
Current No. 1 Wozniacki joined former No. 1s Dinara Safina and Jelena Jankovic, who made first round exits a day earlier. Jankovic lost 7-5, 2-6, 6-3 to Aravane Rezai while Safina was steamrolled 6-0, 6-1 by Marion Bartoli in Hobart.