NEW YORK - Montreal's Eugenie Bouchard fought off four match points before losing 6-4, 2-6, 6-3 to eighth-seeded Angelique Kerber on Thursday in the second round of the U.S. Open.
Bouchard was unable to match her third-round Wimbeldon showing last month.
The teen, ranked 59th in the world, finished with 41 winners and 43 errors against Kerber.
Bouchard broke six times on 14 chances but lost her own serve on seven occasions and committed seven double-faults.
Bouchard saved four match points through winners as she served trailing a set and 3-5 in the third. But a serving error handed Kerber a fifth winning chance, with the German taking the victory on Bouchard's wide forehand.
"It's always disappointing to lose, I'm a bit down about that," Bouchard said . "I felt I played well, I tried to be aggressive. But she's a good counter-puncher, every time I came to the net she passed me.
"My first serve was nowhere as good as it can be, but I made up for some of it with my second serve. But I need to work on my fitness as well as my mental strength. This match showed that I'm close, I was dictating and competing. But I need to get a bit more consistent."
Aleksandra Wozniak of Blainville, Que., playing only her second match since March after last autumn's shoulder injury, faced a huge task against double Grand Slam champion Victoria Azarenka and lost 6-3, 6-1.
"She's a Grand Slam winner and I've not played much tennis," Wozniak said. "This was only my third match and 10 and a half months."
Wozniak said her shoulder is better but it will take time to return to form.
"The shoulder is now 100 per cent," she said. "But I need more match play to get back my game and my rhythm.
"I tried to play like I used to, fast and aggressive. But I need to work on my anticipation, judging the ball. I waited too long today and made errors. But I did return well, I just need to work on the serve."
Wozniak is working to get her match feel back after almost a year of injury hell. She is playing the Open with a protected ranking as she works her way back on the WTA and plans a return to her home event in Quebec City where she suffered her injury.