Clijsters, 29, the former number one and four-time Grand Slam title winner, lost 6-7 (4-7), 6-7 (5-7) to the 18-year-old Robson, ranked 89 in the world. The win took Robson to the last 16 where she would face China's Li Na, seeded ninth. Clijsters, before losing the match on Wednesday, was on a 22-match winning streak in New York.
The Belgian had announced that this year's US Open would be her last tournament as she was planning to spend more time with her four-year-old Daughter Jada and husband Brian. Clijsters had won the US Open in 2005, 2009 and 2010 besides the Australian Open in 2010. Her first retirement from tennis was in 2007 but she came back to the court in 2009 after the birth of her daughter in 2008.
An emotional Clijsters said after the match that New York had been a special place for her as she had played some of her memorable matches there. It was also here where she had won her first Grand Slam title in 2005. She said she wouldn't wish to retire following a loss but nevertheless congratulated Laura for her performance.
The British teenager had fought back into the match after trailing 2-5 in the first set. Robson, a former junior Wimbledon champion, said Clijsters had been her role model and she enjoyed every minute of playing against her.
Clijsters also said she had no regrets over her career which also saw her climbing to the topmost position nine years ago, a feat she repeated last year by becoming the first mother to become No. 1 in the game in February. Clijsters had turned pro in Aug 1997 at the age of 14 and was finished runners in the 1998 Wimbledon juniors' tournament.