After announcing her retirement from tennis earlier this year and that the U.S. Open would be her final tournament, Kim Clijsters had hoped she could finish with a win.

18-year-old British star Laura Robson put an end to those hopes as she defeated Clijsters 7-6 (4), 7-6(5) in the second round, winning two tiebreakers.

Clijsters had previously been undefeated in the last 22 matches she had played at the tournament and had not lost there since 2003. Over her 15 year career, Clijsters won three U.S. Open singles titles and had a record of 523-127.

Clijsters had previously retired in 2007, but returned after having a child and getting married to win the U.S. Open in 2009. She did not play the tournament in 2004, as well as from 2006 through 2008.

''Since I retired the first time, it's been a great adventure for my team and my family,'' said Clijsters to the Associated Press. ''It's all been worth it. But I do look forward to the next part of my life coming up.''Clijsters was seeded at number 23 in the tournament this year and had previously been 28-0 against players out of the top ten rankings before falling to Robson.

The young tennis player from Britain used an array of shots against Clijsters, including an imposing forehand which ended the match and Clijsters' career.

Robson will next face Chinese star Li Na in the third round of the tournament. Clijsters won 41 titles through her career and her most recent major title was at the 2011 Australian Open.