Serena withdraws from showdown vs. Sharapova

   Past French Open champions Maria Sharapova and Garbine Muguruza needed two games combined today to reach the quarterfinals in Paris.
   Unseeded Serena Williams, who has won Roland Garros three times, withdrew from her match against No. 28 seed Sharapova with a chest muscle injury. Later, unseeded Lesia Tsurenko of Ukraine retired because of a leg injury with No. 3 seed Muguruza leading 2-0.
   Williams had been 19-2 with an 18-match winning streak against Sharapova. Off the court, the players have feuded over the years. On Saturday, Williams criticized Sharapova's 2017 autobiography as "hearsay."
   Williams, who had a baby last September, was playing in her first tournament since March and her first Grand Slam tournament since winning the 2017 Australian Open.
   Sharapova advanced to her first Grand Slam quarterfinal since losing to Williams at that stage in the 2016 Australian Open. That was Sharapova's last appearance before serving a 15-month doping suspension.
   Both Williams and Sharapova are scheduled to play in the inaugural Mubadala Silicon Valley Classic, July 30-Aug. 5 at San Jose State. The tournament replaces the Bank of the West Classic, which had been held at Stanford for 21 years.
   In the French Open women's quarterfinals, No. 1 seed Simona Halep will face No. 12 Angelique Kerber, Muguruza will meet Sharapova, No. 13 Madison Keys will play unseeded Yulia Putintseva, and No. 10 Sloane Stephens will take on No. 14 Daria Kasatkina.
   Stephens, a 25-year-old Fresno product now living in Fort Lauderdale, Fla., and Kasatkina, a 21-year-old Russian, will meet after the 5 a.m. PDT match between No. 2 seed Alexander Zverev and No. 7 Dominic Thiem. Tennis Channel will televise the matches.
   Kasatkina ousted No. 2 seed Caroline Wozniacki, coming off her first Grand Slam title in the Australian Open, 7-6 (5), 6-3 in the completion of a match suspended by darkness on Sunday. Stephens, the reigning U.S. Open champion, is 1-1 (1-0 on clay) against Kasatkina.
   In the other men's quarterfinals, No. 1 seed Rafael Nadal will meet No. 11 Diego Schwartzman, No. 3 Marin Cilic will take on No. 5 Juan Martin Del Potro, and No. 20 Novak Djokovic will play unseeded Marco Cecchinato.
   Meanwhile, Katie Volynets of Walnut Creek in the San Francisco Bay Area lost twice to seeded Yuki Naito of Japan in junior matches.
   The 16-year-old Volynets, a U.S. Open girls quarterfinalist last year, fell 6-3, 4-6, 6-3 to No. 10 seed Naito, 17, in the second round and with Natasha Subhash of Fairfax, Va., 6-2, 6-2 to No. 3 Naito and Naho Sato in the first round.