Serena Williams reached the US Open quarter-finals with a 6-0 4-6 6-3 victory over Kaia Kanepi.
Williams took the first set in only 18 minutes and did not drop a point on her first serve but Estonia's Kanepi responded. Williams broke early in the third set as she completed her win in 97 minutes. The 23-time Grand Slam singles champion will now play Czech eighth seed Karolina Pliskova.