Serena Williams returns the ball against Russia's Maria Kirilenko during her Stanford Classic tennis match in Stanford, California, July 28, 2011. [Photo/Agencies]

Russia's Maria Sharapova returns the ball against Slovakia's Daniela Hantuchova during her Stanford Classic tennis match in Stanford, California, July 27, 2011. [Photo/Agencies]

STANFORD, California - Serena Williams and Maria Shar apova have never always seen eye-to-eye but when they face off in the Stanford Classic quarter-finals on Friday, they plan to keep any hostilities confined to the court.

While both maintain nothing less than victory would be a satisfying outcome, Williams said that while it may appear to the outside world that she dislikes her rival, it has never been the case.

"I've never been against her or anyone else on this tour," the American told reporters after her 6-2 3-6 6-2 win over Sharapova's Russian compatriot Maria Kirilenko.

"Just because I'm giving 200 percent and just because I'm fighting and saying 'Come on', I think sometimes the media want to make something out of nothing.

"I'm always saying 'hi' to everyone in the locker room, so I leave it all out there on the court. For me, it's never been anything personal or non-personal."

The pair have played each other eight times, with Williams winning six and the Russian twice. Sharapova beat Williams in the 2004 Wimbledon final but the American has won their last five encounters.

Sharapova admits that while there is mutual respect between them, differences remain on court.

"You both develop as people and players, and have great moments as well as tough ones... but at the end of the day, she has 13 grand slams and I have three," Sharapova said.

The fifth-ranked Sharapova is enjoying an impressive mid-season, winning 17 of her last 19 matches, including a three-set victory over Daniela Hantuchova in the opening round.

She won in Rome, reached the semi-finals at the French Open and then the Wimbledon final, leading the player to believe the radical changes she has made are finally paying dividends.

"I think I'm going in the right direction. I made some tough choices in the last year and changes in my team... had to put a lot of trust into situations which I was not quite comfortable with in the beginning," Sharapova added.

"It was tough and new. Little-by-little, these decisions are paying off," said the Russian, who switched from American coach Michael Joyce to Swede Thomas Hogstedt at the beginning of 2011.