SYDNEY: World No. 2 Simona Halep overcame a nagging Achilles problem to beat Caroline Garcia of France at the Sydney International on Tuesday ahead of next week's Australian Open.

The Romanian withdrew from the Brisbane International last week because of the injury, which also affected her 2015 campaign, and she called the trainer during her second-round match.

Halep, who was given a first-round bye, said the pain was coming and going but she produced some of her best tennis in the deciding set on the way to a 6-4, 2-6, 6-1 victory that set up a quarter-final against Czech fifth seed Karolina Pliskova.

"When you have pain you always get scared because you don't know what is going to happen," she said after her win.

"I felt actually yesterday during the practice same thing. Five minutes pain, five minutes without pain.

"I don't know exactly what this is. MRI showed that I have just an inflammation and I can keep playing, so I will do my best and I will try to be there, to stay focused."

The 24-year-old is one of four leading women players heading to the Australian Open, which begins in Melbourne on Monday, under an injury cloud.

World number one Serena Williams (knee), fifth-ranked Maria Sharapova (arm) and number three Garbine Muguruza (foot) all withdrew from matches in the last week.

Halep said before the clash with the 34th-ranked Garcia she was fit but she looked anything but during her medical time out after the Frenchwoman stepped up the aggression to take the second set.

Halep, though, shrugged off the complaint to storm through the third set, reeling off five straight games and recording her first win of the year when Garcia netted a straightforward mid-court forehand.

"I needed matches to see if I can stay during the match until the end with my achilles," she said.

"I did well today. I'm happy that I could finish. I am happier that in the third set I didn't feel the pain. It means that I can keep working and keep playing with tough opponents."

Earlier Tuesday, Sara Errani rallied from 5-1 down in the second set, saving seven set points, to beat former No. 1 Jelena Jankovic 7-6 (3), 7-6 (8) to advance to the quarterfinals.

"Yeah, it was 5-1, but I had many games with 40-Love, 40-15, and advantage, and so it didn't really feel like 5-1," Errani said. "I was just thinking that I was near my best level, and to just try to keep going, play all the points, and finally was 5-all, and 5-5, 6-all, and really tough the tiebreaker."

Fifth-seeded Karolina Pliskova beat Anastasia Pavlyuchenkova 6-3, 6-0 and eighth-seeded Belinda Bencic defeated Tsvetana Pironkova 6-3, 6-3.

Samantha Stosur also reached the Sydney quarterfinals for the first time in 11 years when she beat Slovakian veteran Daniela Hantuchova 6-4, 6-2. Stosur was runner-up at the tournament in 2005.

In the men's draw, Teymuraz Gabashvili beat seventh-seeded Leonardo Mayer 6-4, 6-3, eighth-seeded Alexandr Dolgopolov beat Thomaz Bellucci 6-1, 6-4 and Nicolas Mahut beat Adrian Mannarino 6-4, 7-5.

At the Hobart International, Eugenie Bouchard continued her injury comeback with a 6-4, 7-5 win over Alison Van Uytvanck. She is playing in only her third tournament since she sustained a concussion when she fell in the dressing room at the U.S. Open in September. Bouchard also reached the quarterfinals of last week's Shenzhen Open.

Second-seeded Camila Giorgi beat Nao Hibino 6-2, 6-3 to reach the quarterfinals.

On a rain-shortened day at the ASB Classic in Auckland, New Zealand, eighth-seeded Robert Bautista Agut beat defending champion Jiri Vesely 6-3, 7-5 and 2008 champion Philipp Kohlschreiber beat Benjamin Becker 7-6 (8), 6-3.

Sam Querrey and Aljaz Bedene had been locked in a marathon match before Bedene was forced to retire while trailing 6-7 (5), 7-6 (10), 2-1 after nearly two hours.