New York • Grit was not going to be enough to get Maria Sharapova through this one.

Not with nine double-faults, including three in a row.

Not with a total of 36 unforced errors.

And certainly not with No. 1-seeded Caroline Wozniacki of Denmark across the net Monday in the fourth round of the U.S. Open, doing "what she does best," as Sharapova herself put it: getting to nearly every ball and hammering it back, stretching points on and on and on until her opponent misses the mark.

It added up to a 6-3, 6-4 victory for 2009 U.S. Open runner-up Wozniacki over Sharapova, who has failed to make it even as far as the quarterfinals at Flushing Meadows since winning the 2006 title.

"I felt like I was playing well out there," Wozniacki said, then made sure everyone understood a key concept by adding, "I made her do those errors."

Indeed, she did. Rare is the opponent who can trade powerful baseline groundstrokes with three-time Grand Slam champion Sharapova and figure out a way to put her on the defensive, but that's exactly what Wozniacki managed to do as early evening shadows crept across the blue court in Arthur Ashe Stadium.

"When she had the opportunity to step in," the 14th-seeded Sharapova said, her voice a barely audible monotone, "she took it and went for her shots."

It's the first victory for Wozniacki in three career meetings against Sharapova, but they hadn't met on the courts since 2008.

In that time, Wozniacki, 20, has grown and built a huge supply of confidence. —

U.S. Open

P Today, 9 p.m., 5 p.m.

TV • ESPN2 —

In short

R Maria Sharapova has 36 unforced errors and nine double faults in loss to Caroline Wozniacki.