Kim Clijsters loses final singles match

Four-time Grand Slam champion Kim Clijsters lost in straight sets to Laura Robson

of Britain in the second round of the U.S. Open on Wednesday, Aug. 29 and will

head into retirement after she finishes playing in doubles at Flushing

Meadows.

2012 US Open - Day 3

NEW YORK, NY - AUGUST 29: Kim Clijsters of Belgium reacts against Laura Robson of Great Britain during their women's singles second round match Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Michael Heiman/Getty Images)

2012 US Open - Day 3

NEW YORK, NY - AUGUST 29: Kim Clijsters of Belgium returns a shot against Laura Robson of Great Britain during their women's singles second round match Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)

2012 US Open - Day 3

NEW YORK, NY - AUGUST 29: Kim Clijsters of Belgium returns a shot against Laura Robson of Great Britain during their women's singles second round match Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)

2012 US Open - Day 3

NEW YORK, NY - AUGUST 29: Kim Clijsters of Belgium returns a shot against Laura Robson of Great Britain during their women's singles second round match Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)

2012 US Open - Day 3

NEW YORK, NY - AUGUST 29: Kim Clijsters of Belgium returns a shot against Laura Robson of Great Britain during their women's singles second round match Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)

2012 US Open - Day 3

NEW YORK, NY - AUGUST 29: Kim Clijsters of Belgium celebrates a point against Laura Robson of Great Britain during their women's singles second round match Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)

Kim Clijsters of Belgium wipes her face during her match against Laura Robson of Great Britain in the second round of play at the 2012 US Open tennis tournament, Wednesday, Aug. 29, 2012, in New York. (AP Photo/Mel C. Evans)

Kim Clijsters of Belgium wipes her face during her match against Laura Robson of Great Britain in the second round of play at the 2012 US Open tennis tournament, Wednesday, Aug. 29, 2012, in New York. (AP Photo/Mel C. Evans)

Kim Clijsters of Belgium reaches for a shot during her match with Laura Robson of Great Britain in the second round of play at the 2012 US Open tennis tournament, Wednesday, Aug. 29, 2012, in New York. (AP Photo/Mel C. Evans)

Kim Clijsters of Belgium reaches for a shot during her match with Laura Robson of Great Britain in the second round of play at the 2012 US Open tennis tournament, Wednesday, Aug. 29, 2012, in New York. (AP Photo/Mel C. Evans)

Kim Clijsters of Belgium looks up after losing to Laura Robson of Great Britain in the second round of play at the 2012 US Open tennis tournament, Wednesday, Aug. 29, 2012, in New York. (AP Photo/Charles Krupa)

Kim Clijsters of Belgium looks up after losing to Laura Robson of Great Britain in the second round of play at the 2012 US Open tennis tournament, Wednesday, Aug. 29, 2012, in New York. (AP Photo/Charles Krupa)

2012 US Open - Day 3

NEW YORK, NY - AUGUST 29: Kim Clijsters of Belgium congratulates Laura Robson of Great Britain after their women's singles second round match on Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)

2012 US Open - Day 3

NEW YORK, NY - AUGUST 29: Kim Clijsters of Belgium waves to the crowd before walking off court following her defeat to Laura Robson of Great Britain after their women's singles second round match on Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)

Kim Clijsters of Belgium sits on the side of the court after losing to Laura Robson of Great Britain in the second round of play at the 2012 US Open tennis tournament, Wednesday, Aug. 29, 2012, in New York. (AP Photo/Mel C. Evans)

Kim Clijsters of Belgium sits on the side of the court after losing to Laura Robson of Great Britain in the second round of play at the 2012 US Open tennis tournament, Wednesday, Aug. 29, 2012, in New York. (AP Photo/Mel C. Evans)

2012 US Open - Day 3

NEW YORK, NY - AUGUST 29: Kim Clijsters of Belgium is interviewed following her defeat to Laura Robson of Great Britain after their women's singles second round match on Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Cameron Spencer/Getty Images)

2012 US Open - Day 3

NEW YORK, NY - AUGUST 29: Kim Clijsters of Belgium signs autographs for fans as she leaves the court following her defeat to Laura Robson of Great Britain after their women's singles second round match on Day Three of the 2012 US Open at USTA Billie Jean King National Tennis Center on August 29, 2012 in the Flushing neigborhood of the Queens borough of New York City. (Photo by Al Bello/Getty Images)