Western e Southern Open: Defending champ Madison Keys upset, Naomi Osaka survives

Third seed Serena Williams and fourth seed Naomi Osaka are the highest seeds left in the Western & Southern Open women’s draw.On Monday, Williams reached the round-of-16 with a three-set win over Arantxa Rus. Greece’s Maria Sakkari is the 23-time Slam champion’s third-round opponent. The 13th seed won against Yulia Putintseva 6-4, 7-6(9) in the second round.Osaka, too, had a tough outing against Czech opponent Karolina Muchova. The Japanese dropped the opening set in the ti