Britain's Harriet Dart and her French partner Diane Parry stunned Olympic champions Sara Errani and Jasmine Paolini on a day of mixed fortunes for British doubles players at the US Open.

Unseeded pair Dart and Parry beat the Italian sixth seeds 7-6 (7-3) 3-6 6-3 on Friday to reach the third round of the women's doubles.

Katie Boulter and Maia Lumsden could not pull off similar upsets against higher seeded opposition respectively in their second-round matches.

Eighth seeds Demi Schuurs and Luisa Stefani overcame Boulter and Anna Kalinskaya 7-6 (10-8) 7-6 (7-5) to reach the third round, while ninth seeds Sofia Kenin and Bethanie Mattek-Sands defeated Lumsden and Anna Siskova of the Czech Republic 6-2 6-1.

In the men's doubles, Wimbledon champions Henry Patten and Harri Heliovaara secured their place in the third round with a 6-0 7-5 victory over Italian Flavio Cobolli and Switzerland's Dominic Stricker.

Neal Skupski and New Zealand's Michael Venus also won their second-round match, with the eighth seeds beating Argentine Guido Andreozzi and Indian N. Sriram Balaji 7-6 (7-4) 6-4.

Mixed doubles top seeds Joe Salisbury and Canadian Gabriela Dabrowski were handed a tough draw in the first round against defending champions Anna Danilina and Heliovaara.

The unseeded Kazakh-Finnish team pulled off a comeback to win 4-6 7-6 (7-5) 10-8.