Kim Clijsters ended her stellar singles career, earlier than expected, going down to Laura Robson 7-6 (4), 7-6 (5) in the second round of the U.S. Open at Flushing Meadows in New York.

Clijsters had announced she would retire from the sport at the end of the U.S. Open, and after going over 20 matches unbeaten on the hard courts of Flushing Meadows, the Belgian bowed out of the game, like she has always played the sport, with a lot of grace and humility.

"One of my biggest dreams came true here in 2005 (when she won her first Grand Slam)," Clijsters said. "It completely feels like the perfect place to retire.

"I just wish it wasn't today.

"Since I retired for the first time, it's been a great adventure for me, my team and my family. And it's all been worth it. A lot of dreams for me have come true because of tennis. But I'm looking forward to the next adventure."

Clijsters said she had no regrets whatsoever, in how her career panned out, and in making the retirement decision. "I mean, after talking and kind of thinking about, you know, the retirement in singles, I'm happy," she said.

"You know, I'm happy that in the last year and a half or even two years, it's been kind of up and down, and I'm happy that I stuck through it and I was able to kind of live a lot of these emotions that I've had in these 18 months or so.

"I'm kind of in a way proud of myself that I was able to do that. So, yeah, I feel happy."

Clijsters will take part in the doubles and mixed doubles events at the U. S. Open, before officially bidding goodbye to the game.

Meanwhile, Maris Sharapova thrashed Lourdes Dominguez Lino 6-0, 6-1.