Top-seeded Maria Sharapova withdrew with a left hamstring injury Saturday during her semifinal match against Ana Ivanovic at the Pan Pacific Open in Tokyo.

Sharapova sought medical assistance before opting out of the match.

Her withdrawal means the fifth-seeded Ivanovic will face No. 2 seed Martina Hingis in Sunday’s final.

Ivanovic was leading, 6-1, 0-1, when Sharapova could not continue.

“I started to feel the tightness at the Australian Open, but this was not the same pain,” said the 19-year-old Sharapova. “After six or seven matches in 14 days, you’re bound to be sore (and) the pain didn’t get any better.”

“It’s unfortunate that she had to retire,” Ivanovic said. “It’s not the way I like to end the match.”