Japan's Mai Hontama upset fifth-seedes Nadia Podoroska of Argentina 6-3, 6-3 in the Round of 16 on Wednesday at the Japan Open in Osaka. Hontama won 80 percent (24 of 30) of her first-serve points, compared to 68 percent (24 of 42) for Podoroska in the match lasting 1 hour, 27 minutes.