From boardroom chic to battling win, Osaka reaches US Open last 16 ↧ ↧ From boardroom chic to battling win, Osaka reaches US Open last 16 Naomi Osaka continued to impress with her style and staying power at the U.S. Open on Saturday as the Japanese 13th seed shrugged off a late Achilles problem to beat Belgian ​Elise Mertens 6-3 3-6 7-5 and reach the fourth round.