Russian Maria Sharapova, who was back on the grand-slam stage after returning from a doping ban, was knocked out of the US Open in the fourth round when she lost 5-7 6-4 6-2 to Latvian 16th seed Anastasija Sevastova on Sunday.

Former world number one Sharapova, who had been granted a wild-card entry into the main draw, toiled through the first set before losing control of the match and hit a total of 51 unforced errors.

Anastasija Sevastova of Latvia shakes hands after winning her match against Maria Sharapova of Russia.Anastasija Sevastova of Latvia shakes hands after winning her match against Maria Sharapova of Russia.