Serena’s Australian Open bid in doubt
Serena Williams beat Bojana Jovanowski in the last 16 of the Brisbane International but then pulled out of the tournament with a sprained ankle that could threaten her Australian Open bid later this month.
The fourth seed wrapped up a 6-2 6-4 win but rolled her ankle and was forced to withdraw after a subsequent scan.
“I'm disappointed to have to pull out,” Williams lamented. “I have been to hospital and it has been confirmed that I have a left ankle sprain that I probably shouldn't play on.
“I'm going to take a couple of days off and see how I feel. I'm still hopeful of playing the Australian Open.”
Top seed and home favourite Samantha Stosur was eliminated by Iveta Benesova, the Czech player triumphing 6-4 6-2.
“Iveta played quite well, but I probably didn't do what I set out to do,” Stosur said.
The other women's quarter-finals saw in-form Kaia Kanepi thrash number seven seed Anastasia Pavlyuchenkova 6-0 6-3 while sixth seed Jelena Jankovic beat Russian Nina Bratchikova 6-3 6-2.
Men's top seed Andy Murray was forced to recover from a set down for the second day in succession to beat Luxembourg's Gilles Muller.
The world number four lost the opening set 6-4 after a dismal final service game but took the second on a tie-break and powered through the decider to win 4-6 7-6 (7/4) 6-0.
The Scot will next face Cypriot Marcos Baghdatis, a 6-3 6-4 winner over fifth seed Kei Nishikori today.
Murray (below) continued to do it the hard way as he reached the last eight
But he responded well to going a set behind, breaking in the first game of the second set courtesy of a superb return on second serve and later producing two big serves denying Muller the chance to serve for the match.
It meant the world number four would instead have to serve to stay in it, but he did so to make it 5-5. A love hold for Muller forced him to repeat the feat, but he duly set up a tie-break and claimed an early mini-break.
Muller twice netted before Murray moved 6-2 up with an outlandish backhand winner, and he took his third set point to take the match into a decider.
He raced to a love hold in the opening game and followed it with another early break en route to a 3-0 lead.
A second break and a hold from 0-30 down meant Muller was the one serving to stay in the match - and he was unable to do so, leaving Murray to complete a final-set whitewash to seal a quarter-final spot.
Third seed Alexander Dolgopolov was another player to face a stern test before eventually overcoming Russia's Igor Andreev 6-7 (3/7) 7-6 (11/9) 6-2. Second seed Gilles Simon beat Sydney teenager James Duckworth 6-3 7-5 but Bernard Tomic kept home hopes alive with a routine 6-1 6-2 win over Japan's Tatsuma Ito.
Radek Stepanek beat Jarkko Nieminen 7-6 (7/4) 6-2 while Santiago Giraldo took a 6-4 6-4 success against Philipp Petzschner.