Clijsters is left reeling after shock defeat to Petrova

The 26-year-old Belgian suffered the worst loss of her professional career as she was thrashed 6-0 6-1 by 19th seed Nadia Petrova under the lights of the Hisense Arena.

There was better news for Clijsters's countrywomen Justin Henin and Yanina Wickmayer, who both secured victories to set up an all-Belgian fourth-round tie.

Third seed Svetlana Kuznetsova had to come from a set down to beat unseeded German Angelique Kerber in a match that finished at 1.45am local time.

Eighth seed Jelena Jankovic also crashed out of the women's draw when she lost to Alona Bondarenko, but the biggest surprise of the day was Clijsters' capitulation against Petrova.

The Russian took just 18 minutes to claim the opening set and a shell-shocked Clijsters never recovered.

"This is something probably you want to forget as soon as possible and go home," the 15th seed said."There were points where I really wanted to break my racquet into pieces."

Henin fought back from a set and a break down against 27th seed Alisa Kleybanova to win 3-6 6-4 6-2 and keep alive her bid to win a grand slam just a month after returning from retirement.

Wickmayer defeated Sara Errani 6-1 6-7 (4/7) 6-3 to continue her remarkable run after the world No 16 was forced to come through qualifying because a ban imposed for failing to comply with doping rules was not lifted in time for direct entry into the main draw.

Bondarenko claimed the biggest scalp in terms of seeding so far when she easily beat Jankovic 6-2 6-3.

Jankovic had won the previous nine meetings between the pair, but 40 unforced errors ensured her tournament ended prematurely.

China's Jie Zheng rounded out a day of upsets as she beat 11th seed Marion Bartoli 5-7 6-3 6-0.

Zheng's victory ensured she replicated her run to the last 16 at Melbourne Park last year where she will meet the 31st seed Bondarenko.