Osaka roars into quarters

Japan's Naomi Osaka pulverised Slovak Dominika Cibulkova 6-2, 6-1 to reach the Pan Pacific Open quarterfinals in Tokyo, Japan, on Wednesday in her first match since her historic US Open triumph. Earlier, sixth seed Garbine Muguruza was upset by American qualifier Alison Riske 6-1, 6-2. Riske advances to face fourth seed Karolina Pliskova, who beat Australia's Daria Gavrilova 4-6, 6-4, 6-4. Second seed Caroline Garcia overcame Russia's Anastasia Pavlyuchenkova 6-4, 2-6, 7-5 to reach the last-eight.