Emma Raducanu struggled with blisters again as she lost in the quarter-finals at the Citi Open.
The 19-year-old made 24 unforced errors as she was beaten 7-6, 6-1 by Ludmilla Samsonova.
Raducanu was clearly impacted by a delay to the start of the match, which got underway just before 11pm local time, but also by the blisters sustained during her gruelling three-hour match against Camila Osorio earlier this week.
She continuously blew on her hands as her error count soared in the second set against Samsonova.
The Russian will now go on to play China’s Xiyu Wang in the Citi Open semi-final.
Severe blistering on Raducanu’s right hand led to defeat in the second round of the Australian Open in January, and the issue reared its head again during Britain’s Billie Jean King Cup Final qualifier in April.
She will be hoping the blisters heal before her US Open title defence gets underway on August 29th.
Raducanu made history at Flushing Meadows last year as she became the first British woman to win a Grand Slam title since Virginia Wade in 1977.
She also became the first ever qualifier, male or female, to win a Grand Slam title.
But Raducanu has struggled to find her form since then, shouldering 13 defeats and 10 victories in 2022 so far, and failing to reach a WTA semi-final.
In a bid to improve her performances before the US Open, Raducanu has linked up with Russian coach Dmitry Tursunov on a temporary basis.
He has previously coached Aryna Sabalenka and Anett Kontaveit on the WTA Tour, helping the latter to a career-high of world number five before their split in June.
But the move caused controversy, with Raducanu warned that the partnership could be used as a propaganda tool by Russian President Vladimir Putin.