Russian top seed Nadia Petrova sent Italian Silvia Farina Elia into the semi-finals when she withdrew from the Gold Coast WTA tennis tournament with injury on Thursday.
Petrova pulled out of the match without hitting a ball after injuring her buttock earlier in the week.
She said she played her first two matches at the tournament hoping the injury would get better, but no improvement left her without a choice.
Petrova said the injury would have little effect on her Australian Open preparations.
"It won't affect my preparations at all," she said. "I'm not disappointed at all. I have two matches under my belt and it's not too bad for just starting the season.
"The Australian Open is coming up and it's more important than the tournament here so it's more important for me to stay healthy for the big one."
Petrova said she intended playing in next week's Sydney International.
Fifth-seed Farina Elia will face Australian Samantha Stosur in the semi-finals after Stosur's 2-6, 6-3, 6-4 win over world No.25 and eighth seed Magdalena Maleeva of Bulgaria.
Stosur moves into consecutive semi-finals of the tournament and is looking to go one better than her loss to eventual champion Ai Sugiyama of Japan last year.
{{/usCountry}}Stosur moves into consecutive semi-finals of the tournament and is looking to go one better than her loss to eventual champion Ai Sugiyama of Japan last year.
{{/usCountry}}Second seed Patty Schnyder of Switzerland easily got past 15-year-old Bulgarian qualifier Sesil Karatantcheva 6-2, 6-3 in her match.