Dane starting to hit top form after up-and-down season and breakup

Caroline Wozniacki trusts her stamina so much that she plans to return to New York in two months to run a marathon.

Maria Sharapova, usually the one wearing down opponents in the third set, sure could not keep up on a steamy Sunday at the US Open. Wozniacki won 6-4, 2-6, 6-2 in two hours, 37 minutes to get back to her first Grand Slam quarterfinal in more than two years - and return to the headlines for reasons other than her personal life.