Samantha Stosur has suffered a blow in her preparations for the Australian Open, losing in the first round of the Brisbane International.
World number nine Stosur fell to Swede Sofia Arvidsson, who won 7-6 (7-4) 7-5 in the joint WTA Premier-ATP 250 event at the Queensland Tennis Centre on Monday.
The early loss is likely to conjure fears of a repeat to Stosur's nightmare form early in 2012, when she suffered first-up defeats on home soil at both the Sydney International and the Australian Open, despite entering the first Grand Slam of the season as reigning US Open champion.
There was another early upset at the Pat Rafter Arena, as qualifier Ksenia Pervak came from a set down to beat eighth-seeded Dane Caroline Wozniacki.
Kazakh Pervak defeated the former world number one 2-6 6-3 7-6 (7-1) in two hours and 48 minutes.
In other women's singles matches, German Sabine Lisicki accounted for Czech Lucie Safarova 6-2 6-4, while American Sloane Stephens downed another Czech, Dominika Cibulkova, 6-2 6-3.
Frenchwoman Alize Cornet ended the challenge of Australian qualifier Bojana Bobusic, rallying from a set down to win 2-6 6-3 6-1.
Puerto Rican Monica Puig completed a bad day for home hopes, the qualifier beating Australian Olivia Rogowska 6-2 6-3.
Italian fifth seed Sara Errani and fourth-seeded German Angelique Kerber also advanced, although the latter needed three sets to get past Georgian Anna Tatishvili.
In the men's competition, Australian representatives continued to fall by the wayside, as Japan's fifth seed Kei Nishikori beat Marinko Matosevic 7-5 6-2.
Cypriot Marcos Baghdatis was tested by Australian wildcard Benjamin Mitchell but ultimately registered a 6-4 6-4 win.
The only success story of the day for the home fans came in the unheralded form of John Millman, who overcame American Donald Young 6-4 6-2.
In other matches, American second seed Ryan Harrison beat Czech Ivo Minar 6-4 6-1, while German Florian Mayer, seeded sixth, saw off Santiago Giraldo of Colombia 6-4 6-4.
Finland's Jarkko Nieminen and American Denis Kudla recorded three-set victories, beating Frenchman Julien Benneteau and Russian Igor Kunitsyn respectively.
Finally, fourth seed Jesse Levine won an all-American match against Steve Johnson 7-6 (7-4) 6-3.