Caroline keeps it simple

Doing what she does best, as Sharapova herself put it,Wozniacki got to nearly every ball and hammered it back,stretching points on and on and on until her opponent missed the mark. 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 thats exactly what Wozniacki managed to do as early evening shadows crept across the blue court in Arthur Ashe Stadium.

Wozniacki has lost only 10 games so far; no one has conceded fewer en route to the US Open quarterfinals since 1999. But here is what might be the most remarkable statistic of all: after making only 10 unforced errors against Sharapova,Wozniacki has made 40 in four matches,and her opponents have made 123.

The other quarterfinal on that side of the draw will be No. 31 Kaia Kanepi of Estonia against No. 7 Vera Zvonareva,who overwhelmed 38th-ranked Andrea Petkovic of Germany 6-1,6-2 Monday night.

Third-seeded Novak Djokovic reached his fourth quarterfinals at the US Open by outclassing No. 19 Mardy Fish 6-3,6-4,6-1. Serbias Djokovic next faces No. 17 Gael Monfils,a 6-4,7-5,7-5 winner over Richard Gasquet in an all-French matchup. Another quarterfinal will pit five-time champion Roger Federer against No. 5 Robin Soderling of Sweden,a two-time French Open finalist whose upset of Federer in that round at Paris this year ended his record streak of reaching the semifinals at 23 consecutive Grand Slam tournaments.

Meanwhile, Leander Paes and his Zimbabwean partner Cara Black suffered a 3-6 4-6 straight-set defeat against Anna-Lena Groenefeld and Mark Knowles to bow out.