Former world number one Serena Williams suffered an injury scare ahead of the Australian Open after she badly twisted her ankle at the Brisbane International.

Former world number one Serena Williams suffered an injury scare ahead of the Australian Open after she badly twisted her ankle at the Brisbane International on Wednesday, while top seed Samantha Stosur was bundled out early for the second successive year.

Williams twisted her left ankle late in her second round match against Serbia's Bojana Jovanovski and needed about 10 minutes of treatment including having her ankle restrapped and braced, before she went on to secure a 6-2 6-4 victory.

She is due to meet Slovakia's Daniela Hantuchova in the quarter-finals though the injury will create some doubt as to whether the 30-year-old American will be in top form as she attempts to win her sixth Australian Open title at Melbourne Park later this month.

Stosur, who beat Williams in the U.S. Open final last year to claim her maiden grand slam title, continued her poor run of form in her hometown losing 6-4 6-2 to Czech Iveta Benesova.

It was the second successive year the world number six has been the top seed at Brisbane and lost in the second round. Last year, she lost to compatriot Jarmila Gajdosova.

“Hopefully it was just a bad day and I will bounce back next week and the week after,” Stosur told reporters. “Of course it's disappointing. I never wanted to go out in this round again. I don't want to dwell on it.

“It's back to the practise court and keep working hard and do whatever I can to set up myself up for the summer.

“It's not the ideal start but I am not going to panic and think it's all lost.”

Benesova, who had never beaten Stosur in their previous four meetings, will now meet Australian Open champion Kim Clijsters in the quarter-finals.

Men's second seed Gilles Simon had no problems dispatching Australia's James Duckworth 6-3 7-5 to move on to the quarter-finals.

The Frenchman joins Uzbekistan's Denis Istomin in the last eight after he advanced with a walkover following Tommy Haas's withdrawal with a calf injury.

Men's top seed Andy Murray meets Gilles Muller later on Wednesday.– Reuters