Reigning Wimbledon champion Marketa Vondrousova is in doubt for the Australian Open after withdrawing from the Adelaide International with a right hip injury.
The world No.7, who last year became the All England Club's first unseeded ladies' singles champion in the Open Era, withdrew just hours before her scheduled first-round clash with Russian qualifier Aliaksandra Sasnovich on Tuesday night.
Taylor Townsend will take her place in the draw.
In other matches, Perth teenager Taylah Preston gave former world No.4 Caroline Garcia a massive fright and the Memorial Drive crowd plenty to cheer about before going down swinging.
After waltzing through the second set, 18-year-old Preston moved up a break in the third to be on the cusp of the biggest win of her young career before Garcia peeled off the last five games to prevail 6-4 1-6 6-3.
Garcia's serve betrayed her for large stretches and she struggled to convert multiple break-point opportunities until late in the match when Preston finally ran out of puff.
Preston spent much of the clash standing on the baseline and bossing rallies with her signature backhand, earning the praise of her more experienced French opponent.
"She's a very good player and a fighter," Garcia said.
"If she keeps going and improving, I think she's going to have a very bright future."
Garcia will play sixth seed Jelena Ostapenko in the round of 16 after the aggressive Latvian overpowered Romania's Sorana Cirstea 2-6 6-2 6-4.
The fiery Ostapenko, who made headlines last week in Brisbane for calling Norwegian chair umpire Julie Kjendlie "blind" during her loss to Victoria Azarenka, started shakily on Tuesday before showing composure - not always her greatest strength - when it mattered.
"I feel like I was sleeping in the first set," Ostapenko said.
"I'm not a morning person; I needed time to get into the match.
"When I start to take time and be a bit more calm, I play better.
"It sounds funny because I'm very emotional but I play better when I'm calm."
Qualifier Katerina Siniakova pulled off a major upset when she thrashed fellow Czech and former world No.1 Karolina Pliskova 6-2 6-1.
Siniakova, more regarded as a doubles player having won seven majors in that format - including the last two Australian Opens - fell behind 0-2 against her more heralded countrywoman before reeling off the next 10 games and 12 of the last 13.
Pliskova, who conceded the lopsided victory with a tired double fault, appeared troubled at times by her problematic left wrist.
Earlier, 35-year-old Laura Siegemund continued her dream start to 2024 by following her successful United Cup campaign for Germany in Sydney with a surprise 6-7 (1-7) 6-4 6-4 win over seventh seed Liudmila Samsonova.
Eighth-seeded Veronika Kudermetova moved into the round of 16 after outclassing American Ashlyn Krueger 6-2 7-5.
