Kerber won her 83rd match on grass in her career in just over an hour in what was her 51st consecutive Grand Slam main draw participation.
The 24-year-old from Japan won in straight sets for the second day in a row, this time against 13th seed Angelique Kerber 6-2, 6-3.
Spain’s Paula Badosa beat Victoria Azarenka in a gruelling final to win the prestigious Indian Wells title on her tournament debut on Sunday.
The World No.27 went past the German player in straight sets to book a spot in her second WTA 1000 semifinal of the year.
Leylah Fernandez has beaten three top 10 players and is looking good for winning the US Open title.
The US Open 2021 saw Angelique Kerber get knocked out in the fourth round while the men's top seeds did not suffer a jolt.
Leylah Fernandez dismissed defending champion Naomi Osaka 5-7, 7-6, 6-4, to break through to the Round of 16 of a major for the first time.
Coco Gauff survived a scare before going past Magda Linette with a 5-7, 6-3, 6-4 victory at the US Open.
Coco Gauff survived a scare before going past Magda Linette with a 5-7, 6-3, 6-4 victory at the US Open on Monday.
The Japanese player came from a set down to beat the American teenager in her second-round clash at the Western & Southern Open.