Eighth seed and former World No 1 Caroline Wozniacki became the biggest casualty of the first round when she crashed out 6-2, 6-2 to Romania’s Irina-Camelia Begu.
It was another low in a miserable year for the Dane, who also lost in the first round of Wimbledon, but there were extenuating circumstances as she had her right knee heavily taped.
Wozniacki sustained the injury bidding for her fifth straight New Haven title last week and pulled out during her semi-final against Maria Kirilenko.
The 22-year-old said: “You always want to go in and do your best no matter what’s happening out there. I tried.
“I didn’t play particularly well, made too many errors. It’s unfortunate because it’s a huge tournament, a tournament you want to play well in. I think it’s a temporary issue. Hopefully it will get better quickly. It’s frustrating to have some injuries, but it happens to everyone. It’s just about moving on.”
Venus, Serena advance
Meanwhile, Serena Williams, the champion in 1999, 2002 and 2008, and twice a runner-up, was just as ruthless in the concluding match on Arthur Ashe Stadium, sweeping past US compatriot Coco Vandeweghe 6-1, 6-1. The Wimbledon and Olympic champion, who has 14 Grand Slam titles to her name, next tackles Spain’s Maria Jose Martinez Sanchez.
Fellow US veteran and sister Venus , the 2000 and 2001 winner, also won an all-American match-up, beating wildcard Bethanie Mattek-Sands 6-3, 6-1.
Azarenka storms into Rd 3
World No 1 Victoria Azarenka advanced to the third round by defeating Belgian qualifier Kirsten Flipkens 6-2, 6-2 in only 65 minutes. Reigning Australian Open champion Azarenka, who has reached the last eight in every Grand Slam event except the US Open, will next face Chinese 28th seed Zheng Jie, who beat Slovakian qualifier Magdalena Rybarikova 6-3, 6-1.