 where quarterfinals action in men's and women's singles tennis began yesterday at Wimbledon. On the men's side, five-seater Daniil Medvedev upset one-seater Yannick Sinner in a thrilling five-set match. Three-seater Carlos Alcaraz defeated 12-seater American Tommy Paul in four sets. On the women's side, 19-seater American Emma Navarro was bounced in straight sets by seven-seater Yasmin Paolini. Donna Vecchick, or Vecchick,