Fourth-seeded Maria Sharapova of Russia advanced easily into the semi-finals of the Western & Southern Open with a 6-3, 6-2 win over 10th-seeded Samantha Stosur on Friday.
The seventh-ranked Sharapova, who lost in last year's finals to Kim Clijsters, won a challenge on match point to improve to 3-0 this year and 9-0 in her career against Stosur.
The 10th-ranked Stosur was making her first appearance at this U.S. Open warmup tournament after losing in the final last week at Toronto.
Sharapova will play the winner of the match between unseeded Daniela Hantuchova of Slovakia and No. 2-seeded Vera Zvonareva of Russia, the highest seed remaining in the tournament.