Injury forces Serena out of Brisbane International

Former world number one Serena Williams suffered an injury scare less than two weeks ahead of the Australian Open on Wednesday when the American was forced out of the Brisbane International with a badly twisted ankle.

There was also bad news for home favourite and top seed Samantha Stosur, who was bundled out early for the second successive year.

Men's top seed Andy Murray was in danger of joining Stosur in an early exit when he dropped the first set against Luxembourg's Gilles Muller before he fought back through a second set tiebreak then blitzed the decider to run out a 4-6, 7-6, 6-0 winner.

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

The American had scans later which confirmed she would need to withdraw from the tournament.

"I'm disappointed to have to pull out of the Brisbane International," Williams said in a statement. "I'm still hopeful of playing the Australian Open," it added.

Stosur continued her poor run of form in her home town losing 6-4, 6-2 to Czech Iveta Benesova.

Meanwhile, Roger Federer staked his claim as one of the favourites for the Australian Open title by romping into the second round of the Qatar Open, while rival Rafael Nadal survived a scare in windswept Doha.

Federer thumped Russian Nikolay Davydenko 6-2, 6-2 in less than hour.