Heather Watson was completely outplayed as she lost to Romania's Sorana Cirstea in the first round of the US Open.
After facing Maria Sharapova, Li Na and Simona Halep on previous visits to New York, a meeting with Cirstea appeared to offer Watson a chance of progress.
But the British number one held serve just once as she went down 6-1 6-1 in 54 minutes at Flushing Meadows.
It was a superb performance from the unseeded Cirstea, who had only won 10 times this year heading into the match.
"She hasn't been in great form and I've been having a great year, and I didn't expect to play like this," said Watson.
"I thought I was playing pretty well in practice, but it's a Grand Slam and everybody is going to bring it no matter how they're feeling."
Cirstea has dropped from 22nd in the world to 80th this year, in marked contrast to Watson's 35 wins and a ranking on the rise at 45.
Watson only held her serve once against Sorana Cirstea
However, the former US Open junior champion's positivity disappeared quickly as she appeared shaken by the Romanian's strong start on Court 13.
Cirstea hit three aces in her second service game to stamp her authority on the contest and Watson, already feeling the pressure, then double-faulted on break point to fall 3-1 behind.
The 22-year-old from Guernsey fought off two more break points in game six but could do nothing about a flashing forehand winner from Cirstea on the third, and there was no way back.
Despite managing to recover an early break, the second set was a disaster for Watson.
She failed to win a single point on her second serve - ending with a woeful 12% on that key statistic - made five double faults and 15 unforced errors.
"It can't get much worse," Watson was heard to say at one point as the match raced away from her and, when another double fault offered Cirstea two match points, the Romanian cracked a forehand winner past the helpless Briton.
"It was an opportunity on paper but she still played very well, and I give her a lot of credit," said Watson. "She served well, hit quite a few aces, me not so much.
"I couldn't find my serve, I'm not quite sure why, but I've got to look back and improve on that."
She added: "It's disappointing leaving after a first-round loss here, especially after my year and the confidence I've gained.
"But it's just another week, and I'm going to have a lot more weeks."