Heather Watson was shocked by her poor performance against Sorana Cirstea in the first round of the US Open.
Nothing went right for the British number one, who won just 12 per cent of second serve points in a 6-1 6-1 loss that lasted 54 minutes.
Watson said: "The first few games I was okay and then as soon as I got broken in that first set she stayed playing well the whole rest of the match and I didn't play very well.
"I made a lot of errors, a lot of double faults. It was partly because she was hitting some good shots, so maybe I tried to go for a winner too soon.
"It was just over very quickly. She hasn't been in great form and I've been having a good year so I didn't expect to play like this, I didn't prepare to play like this. I thought I was playing pretty well in practice."
Watson has had an excellent season, climbing from a low of 161 in the rankings at the start of February to 46 and posting her first two wins over top-20 players.
Cirstea, on the other hand, has slumped from 21 a year ago to 80 now and this looked a good first-round draw for Watson.
But the Romanian began the match showing form of old, thumping aces and forehands and leaving Watson reeling.
It did not help that the British player, who has developed her own attacking game to great effect this season, was struggling to find her first serve.
"It was an opportunity on paper but she still played very well today and I give her a lot of credit," said Watson.
"Also she served well, hit quite a few aces, and me not so much. I couldn't find my serve. I'm not quite sure why but I've got to look back and try to improve on that.
"It's definitely the best she's played against me but I like playing her, I usually play quite well against her, but she didn't give me any breathing room."
From 1-1, Watson lost six games in a row and, although she seemed to get a foothold with a break of the Cirstea serve in the second game of the second set, it was a false dawn.
Watson had beaten Cirstea in their three previous meetings, most recently in Fed Cup earlier this year, and in 2012 in Miami she won from 5-0 down in the deciding set.
But a comeback never looked on the cards this time and Cirstea took her first match point with another forehand winner.
Watson's statistics made miserable reading, with eight double faults, six winners and 23 unforced errors adding up to a very bad day at the office.
The 22-year-old still has not won a match at Flushing Meadows since winning the junior title in 2009 and will look to put this one behind her when she heads to Asia for the series of tournaments out there next month.
She said: "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.
"I like playing in Asia. I like the courts and I like the food."
The other positive for Watson is she has almost no points to defend for the rest of the year and is hoping to boost her ranking enough to be seeded at the Australian Open in January.
Watson's defeat leaves Andy Murray once again as the only British singles player left in the tournament.