Cincinnati - World No 1 Caroline Wozniacki's disappointing preparations for this month's US Open continued on Wednesday as she exited the WTA tournament here, losing 6-4, 7-5 to young American Christina McHale.
Wozniacki, 21, suffered a similar collapse as she did last week, when she went out in the second round in Toronto, letting a 5-1 lead slip in the second set.
Wozniacki, who holds the No 1 ranking despite disappointing exits at the French Open and Wimbledon, had only returned to action in Toronto after a month out with a painful shoulder.
Wozniacki, who has been in the news of late for being the new girlfriend of US Open golf champion Rory McIlroy, has not won a match since Wimbledon (she received first round byes in Toronto and here) where she went out in the last 16.
The US Open, the final of which Wozniacki reached in 2009, begins on August 29.