World number one Maria Sharapova struggled with her serve again before beating Japan's Ai Sugiyama in three sets to reach the Pan Pacific Open semifinals on Friday.
The Russian top seed, who hit 17 double faults in three sets yesterday, committed another 14 double faults before finally seeing off Sugiyama 4-6, 6-0, 6-1.
In the semi-finals on Saturday, Sharapova will take on fifth seed Ana Ivanovic of Serbia, who eliminated her compatriot and fourth seed Jelena Jankovic 3-6, 6-4, 6-2.
The other semi will be a re-match of last year's final between Swiss former world number one Martina Hingis and defending champion Elena Dementieva of Russia.
"I felt worried about my serve too much in the first set. That was the reason for me not being aggressive enough. Obviously some part of my game was off and in this tournament it's my serve," said Sharapova.
"But I thought I did a good job just focusing on what I have to do, even if I gave her many free points off my serve."
"I played enough matches in the last couple of weeks. Getting into a Grand Slam final (at the Australian Open) definitely gave me some confidence," added the US Open champion.