Wimbledon and Olympic champion Serena Williams turned her left ankle in a doubles match at the US Open on Wednesday to cast a shadow over her second-round singles clash.
There was no immediate indication regarding the extent of the injury from Williams but she was treated twice and played with a bandage on her ankle after trainers examined it.
While it was a setback, Serena teamed with sister Venus to thrash compatriots Lindsay Lee-Waters and Megan Moulton-Levy 6-4 6-0 in 63 minutes to reach the second round of the women’s doubles tournament.
Serena will face Spain’s Maria Jose Martinez Sanchez in the women’s singles second round on Thursday.
The biggest casualty of the day, however, was three-time champion Kim Clijsters, whose retirement came earlier than expected when she was upset by British teenager Laura Robson 7-6 (7-4) 7-6 (7-5) in the second round.
Clijsters, whose grand slam title haul also includes last year’s Australian Open, had not lost at the US Open since falling to compatriot Justine Henin in the 2003 final as she enjoyed a 22-match winning streak in New York.
Robson, who was age five when Clijsters first played in New York, will next face Chinese ninth seed Li Na, who dispatched Australia’s Casey Dellacqua 6-4 6-4 in 87 minutes.
World No.1 Victoria Azarenka, this year’s Australian Open champion, reached the third round while defending champion Samantha Stosur and third seed Maria Sharapova, the reigning French Open champion, advanced with ease as well.
Azarenka defeated Belgian qualifier Kirsten Flipkens 6-2 6-2 in only 65 minutes for her 50th match victory of the year.
Azarenka, who has reached the last eight in every grand slam event except the US Open, will next face Chinese 28th seed Zheng Jie.
Australian seventh seed Stosur took an hour to beat Romanian qualifier Edina Gallovits-Hall 6-3 6-0 to book a clash with US 31st seed Varvara Lepchenko.
Russian third seed Sharapova ripped through Spain’s Lourdes Dominguez Lino 6-0 6-1 to book a meeting with 21-year-old US wildcard Mallory Burdette, ranked 252nd, who advanced with a 6-2 6-4 victory over Czech Lucie Hradecka.
In the men’s draw, Britain’s third-seeded Andy Murray became the first man to reach the third round as he fired 10 aces in a 6-2 6-1 6-3 romp over Croatian Ivan Dodig.
Spanish fourth seed David Ferrer, Argentine seventh seed Juan Martin del Potro and US ninth seed John Isner won their openers on the Flushing Meadows hardcourts.
The US Open featured nine men’s comeback triumphs from two sets down in the first round, matching the record from 1989, including Serbian ninth seed Janko Tipsarevic’s 4-6 3-6 6-2 6-3 6-2 victory over Frenchman Guillaume Rufin.
And Australian Lleyton Hewitt, the 2001 US Open champion, reached the second round by dispatching Germany’s Tobias Kamke 4-6 6-2 6-1 6-4.
Ferrer, whose best grand slam showing was a 2007 US Open semi-final run, beat South African Kevin Anderson 6-4 6-2 7-6 (7-3) to reach a second-round match against Dutch qualifier Igor Sijsling.
Isner, the top American hope to end a nine-year US men’s grand slam title drought, struggled to subdue Xavier Malisse 6-3 7-6 (7-5) 5-7 7-6 (11-9).
Del Potro, the 2009 US Open winner, advanced over France’s Florent Serra 6-4 7-6 (7-4) 6-4.