Serena raises her game to beat Bartoli, Nadal wins

NEW YORK, Sep 2 (Reuters) Twice former champion Serena Williams advanced to the US Open quarter-finals with a 6-3 6-4 victory over Marion Bartoli today, raising her game in time for another possible championship run.

The eighth-seeded Williams had 10 aces, landed 73 percent of her first serves and blasted 32 winners against the Wimbledon finalist to play her best match of the tournament.

''Each match I feel like I've gotten better,'' said Williams.

''I'm still not near where I want to be. But I feel like I'm doing better, which is important.'' On the men's side, second seed Spaniard Rafael Nadal showed no lingering effects from a nagging knee injury with a 7-6 6-2 6-1 victory over Frenchman Jo-Wilfried Tsonga.

Nadal had only 14 unforced errors and never lost his serve against the 74th-ranked Tsonga.

In the fourth round, Nadal will face compatriot David Ferrer, who needed just under four hours to defeat Argentine David Nalbandian 6-3 3-6 4-6 7-6 7-5.

In a mild upset, Argentine Juan Ignacio Chela tamed Croatian 12th seed Ivan Ljubicic 6-4 6-7 2-6 6-3 6-3 in three-hours, 44-minutes.

The hard-hitting Ljubicic had 80 winners and 64 unforced errors but was unable to close out the steadier Chela, the 20th seed who had just seven errors in the final two sets.

Venus Williams will play fifth seed Ana Ivanovic and world number one Justine Henin will face 15th seed Dinara Safina later today.

Serena's form had been patchy during her first three matches, even though she had not lost a set. But against Bartoli, her play improved dramatically.

Bartoli had trouble with Serena's serve, breaking the American only once during the 76-minute match.

''When it's coming 125 miles (an hour) or something, I didn't even see the ball coming up,'' the Frenchwoman said. I can't see if it's a middle or side serve it's coming so fast.'' If Henin beats Safina, she will face Serena in a highly anticipated quarter-final match-up. Henin, the 2003 Open champion, had knocked Serena out in both the French Open and Wimbledon quarters this year.

''I'm going in feeling like I don't have anything to lose,'' said Serena. ''I'm excited about the prospect of meeting her again. She's playing well and fighting for everything. She believes that she can win.'' Reuters BJR VP0220