Johanna Konta has crashed out of the US Open after losing to world number 78 Aleksanda Krunic in the opening round.
Konta, the seventh seed in New York, looked out of sorts on the Grandstand court, making 42 unforced errors before going down 4-6 6-3 6-4 to the Serbian.
The Brit made just 45 per cent of her first serves, allowing Krunic, who reached the fourth round here three years ago, to take advantage from the baseline.
"I can't take anything for granted"
"I don't think I necessarily played my best tennis, but my opponent also had something to say about that," said Konta after the match.
"She played very freely, I felt, and she moved incredibly well. She made it very tough for me to be able to get any easier points.
"I don't take anything for granted. I think it would be quite obnoxious of me to come in here expecting I have a right to be in the second week."
Krunic, 24, will now face Croatia's Ajla Tomljanovic in the second round, and will now hope to replicate her run to the last 16 three years ago.
Early lead slips away
For Konta, it was a disappointing way to go out of the final major of year, especially as she could have been crowned the new world number one with a run to the final.
The Brit appeared in control early on, racing to a 4-1 lead with a double break.
Krunic did manage to close the gap by winning the next two games, however Konta hung on to take the opener.
However, the Brit continued to look unconvincing, with her first serve percentage dropping to an alarming 39 per cent in the second set.
Krunic sensed her opportunity, winning three games in a row from 3-3 to level the match at a set apiece.
Konta held on to a lengthy service game in the fifth game of the decider to move 3-2 ahead, however she couldn't pull away.
Two games later, the Serbian breached Konta’s serve for the fifth time before closing out the match, which lasted two hours and 16 minutes.
Mixed day for the Brits
Earlier in the day, Britain’s number two Heather Watson was knocked out following a 6-4 6-4 defeat to France’s Alize Cornet.
There was better news on the men’s side, as Kyle Edmund progressed with a comprehensive victory over world number 36 Robin Haase.
Meanwhile, qualifier Cameron Norrie also made it through after opponent Dmitry Tursunov retired at 7-6 (9-7) 6-1 down.