Top-seeded Victoria Azarenka reached the US Open quarter-finals for the first time with a straight-sets victory over Anna Tatishvili.
Azarenka repeated a 6-2 scoreline in both sets to ensure a routine passage to the last eight, breaking Tatishvili's serve seven times in the process.
The Australian Open winner will now face Sam Stosur, the defending champion at Flushing Meadows, who beat British teenager Laura Robson earlier on Sunday 6-4 6-4 in a hard-fought encounter.
