Mason, OH – Former world No. 1 and 2010 runner-up Maria round Russian winners Thursday at the $2.05 million Western & Southern Open, a U.S. Open Series event.
The fourth-seeded Sharapova drilled 14th-seeded fellow Russian Svetlana Kuznetsova 6-2, 6-3, while the second-seeded 2010 U.S. Open runner-up Zvonareva leveled Croatian qualifier Petra Martic 6-2, 6-2 in exactly one hour on the hardcourts at the Lindner Family Tennis Center.
Sharapova will face tough Aussie Samantha Stosur in Friday's quarterfinals, while Zvonareva, who titled here in 2006 and was the Cincinnati runner-up in 2004, will take on Slovakian veteran Daniela Hantuchova.
Last year's French Open runner-up Stosur upended this year's French Open champion Li Na in 6-4, 3-6, 6-4 fashion on Day 4. The 10th-seeded Stosur was last week's Toronto runner-up to Serena Williams, who pulled out of the draw here on Wednesday due to a foot problem.
Another Thursday upset came when Hantuchova took out eighth-seeded French slugger Marion Bartoli 6-3, 5-7, 6-3.
The 2011 Cincinnati champion will collect $360,000.