Former world No.1 Ana Ivanovic has slumped to her second first-round exit in as many weeks after falling 6-4 6-2 to Karolina Pliskova on day one of the Sydney International.
In worrying signs for Ivanovic, the Serbian star struggled to keep pace with the world No.11, and even had trouble with her ball toss.
She was bundled out by world No.122 Naomi Brady in her first match in Brisbane last week.
Pliskova is now on course to meet top seed Simona Halep in the quarter finals should the draw go to the seeding plan.
The 23-year-old Czech has a strong chance of avenging her final loss last year after both defending champion Petra Kvitova and second seed Agnieszka Radwanska.
Kvitova succumbed to a stomach bug she picked up at the Shenzhen Open last week, while Radwanska, who won the title in China, is recovering from a left leg injury.
“I’m really disappointed to have to withdraw from the Apia International Sydney but unfortunately I am still not feeling well,” Kvitova said in a statement on Sunday.
Radwanska said she needed the rest.
“I’m really sorry that I can’t play the Apia International Sydney this week. I am feeling very confident in my game at the moment and the results are there, but after five matches in the past week my leg needs some recovery time,” Radwanska said.
The women’s top four – Serena Williams (knee), Halep (Achilles), Garbine Muguruza (foot) and Maria Sharapova (forearm) – have all endured a troubled lead-up to the Open.
Australian No.1 Sam Stosur is also battling a wrist problem.
World No.10 Angelique Kerber is the only member of the top ten to not withdraw, lose first round, or retire through the first few weeks of the 2016 season.
Earlier on day one in Sydney, 2014 champion Tsvetana Pironkova upset Lesia Tsurenko 7-6 6-2 to move to the second round, where she’ll be joined by dual Wimbledon champ Svetlana Kuznetsova, who lost just two games in a 6-2 6-0 romp over Australian wildcard Tammi Patterson.
Meanwhile, former world No.1 Jelena Jankovic rebounded from a first-round exit in Brisbane to score a 6-3 6-4 win over American Coco Vandeweghe.