Defending champion Angelique Kerber was knocked out in round one of the US Open by Japanese teenager Naomi Osaka.
The German sixth seed was overpowered by the 19-year-old world number 45, who won 6-3 6-1 under the roof on Arthur Ashe Stadium at Flushing Meadows.
It continues a disappointing year for 29-year-old Kerber, who has not won a title since her victory in New York 12 months ago.
She was also beaten in the first round of the French Open.
More to follow.