NEW YORK, Sept 1 (Reuters) - Coco Gauff said her defeat to former champion Sloane Stephens at the U.S. Open on Wednesday had highlighted the shortcomings in her game but the 17-year-old is convinced she will get her hands on a Grand Slam title one day. The American became an overnight sensation when she reached the fourth round of Wimbledon in 2019 as a qualifier and she has steadily climbed up the rankings, reaching number 23. However, she was no match for 2017 champion Stephens in their first career meeting, going down 6-4 6-2 to the 28-year-old in the second round. "The goal is always to win, so obviously I think I can do a lot better," Gauff said. "I think today"s match showed what I need to improve on. "Singles-wise, I think I have a lot to work on. I"m going to go back to work once this is over." Gauff said reaching a maiden quarter-final at the French Open was the standout for her in 2021, during which she also made the fourth round at Wimbledon. "I feel like I"ve learned that I"m capable of making it far in slams," said Gauff, who also won her first WTA claycourt title in Parma this year. "I think if I tighten up a few things, that I"m capable of winning one. "The past couple of slams I"ve lost to players that have gone to the quarters or won eventually, so it shows that I"m there. "I feel like there"s just an experience lacking that I have. I definitely think it shows. I think that I just need to play more matches so I feel more comfortable on the pressure moments."