Britain's Harriet Dart remains in the hunt for a place in the US Open main draw after a gutsy comeback win in the first round of qualifying.

The British number four must win two more matches this week to qualify for the final Grand Slam event of the year, which starts in New York on Monday.

But Heather Watson is out after losing 6-3 6-2 to Ukraine's Dayana Yastremska.

British number three Watson, 31, was given a tough draw against 12th seed Yastremska and misses out on the main draw at Flushing Meadows for the second successive year.

Dart, ranked 140th, will face Belgian world number 86 Yanina Wickmayer - seeded third - in the second round.

Three other Britons - Lily Miyazaki, Liam Broady and Jan Choinski - play their opening qualifying matches on Wednesday.

Katie Swan also had a place in the event but pulled out last week with a back injury.

The third and final qualifying round takes place on Friday, with 16 women and 16 men progressing to the main draw.

Six British players - Andy Murray, Cameron Norrie, Dan Evans, Jack Draper, Katie Boulter and Jodie Burrage - earned direct entry on the basis of their rankings inside the world's top 100.