Williams sisters on collision course

NEW YORK -- When you hear about Serena and Venus Williams overpowering opponents, as happened Sunday at the U.S. Open to two recent Grand Slam finalists, it's easy to forget that the sisters are, indeed, individuals.

And as similar as their on-court styles might seem, all stinging serves and gargantuan groundstrokes, they are not quite carbon copies.

That point was driven home by their father and coach, Richard, who sat courtside for the final game of Serena's 6-3, 6-4 victory over Wimbledon runner-up Marion Bartoli, then watched Venus' 6-4, 6-2 win against French Open runner-up Ana Ivanovic.

"Serena reminds me of a pit bull dog and a young Mike Tyson, all in one," Dad said Sunday. "Venus reminds me of a gazelle that's able to move, prance and jump. Venus looks as if she is really enjoying herself out there more than Serena is right now. If they get by everyone and meet each other, it will be an interesting match."

Another all-Williams showdown is indeed nearing at Flushing Meadows, although unlike six previous meetings for major titles -- Serena leads 5-1 in those finals; Venus leads 7-6 overall -- this one would be a semifinal.

"That would be awesome because it would mean that there is a Williams in the final," Venus said. She also noted: "We have one more step."

For Serena, it's a familiar one. She will face No. 1 Justine Henin in the quarterfinals at a third consecutive major, having lost to her at the French Open and Wimbledon.

"Yeah, we know each other pretty well," Henin said after beating No. 15 Dinara Safina 6-0, 6-2 at night. "I know everyone was waiting for that match, and here we are."

The older Williams' quarterfinal opponent will be No. 3 Jelena Jankovic, who defeated No. 19 Sybille Bammer 6-4, 4-6, 6-1. Jankovic won her past three matches against Venus, including at Wimbledon in 2006 and the French Open this year.

The day's biggest surprise came in the final match, when 88th-ranked Ernests Gulbis of Latvia easily ousted No. 8-seeded Tommy Robredo 6-1, 6-3, 6-2. Gulbis, who turned 19 on Thursday and is the lowest-ranked man left in the draw, came to New York having lost in the first round at 10 of his 11 tournaments in 2007.

No. 2 Rafael Nadal, meanwhile, advanced to the fourth round without a hitch in his step -- his taped-up knees have been bothering him -- or his game, beating Jo-Wilfried Tsonga 7-6 (3), 6-2, 6-1.

Next for Nadal is a fellow Spaniard, No. 15 David Ferrer, who was one point from defeat before coming back to eliminate 2002 Wimbledon finalist David Nalbandian 6-3, 3-6, 4-6, 7-6 (5), 7-5 in a match that included a 24-point game.

Winners also included No. 3 Novak Djokovic, No. 17 Carlos Moya, No. 20 Juan Ignacio Chela, No. 23 Juan Monaco and unseeded Stanislas Wawrinka, who followed up his victory over Marat Safin by defeating Robby Ginepri of the United States 5-7, 6-4, 4-6, 6-4, 6-3. Moya also won in five sets, edging Philipp Kohlschreiber 4-6, 7-5, 7-6 (5), 4-6, 6-4, while Djokovic got past Juan Martin del Potro 6-1, 6-3, 6-4 at night.

"Hopefully I play even better the next round," Djokovic said.

Both Williams sisters are two-time U.S. Open champions and both are getting in a groove as this Grand Slam goes on, just as Serena did en route to her eighth major title at the Australian Open in January, and Venus did en route to her sixth major title at Wimbledon in July.

"I'm still not where I want to be -- or near," Serena said. "But I feel like I'm doing better, which is important."

Who needs tuneup tournaments?

She pulled out of every event in the 1½ months since spraining a ligament in her left thumb at Wimbledon, and while that hand is fine now, her father indicated something else is wrong.

"Serena has a few problems that we haven't talked to no one about," Richard Williams said, but wouldn't elaborate. "I think she's done a marvelous job of hiding it. Extremely marvelous."

When Serena is on the court, there's no protective tape on her left thumb or anywhere else, although there was a Band-Aid wrapped around a toe when she walked out of her news conference in flip-flops.

Asked whether something was affecting her physically, Serena replied: "I would be the last person to tell you, just in case Justine or Safina reads it, and they're like, 'Uh, I know what to do.' "

Her two-fisted backhand was off and her footwork was slow at the start against the 10th-seeded Bartoli, who broke in the first game and went up 2-0 with two aces. Then Serena snapped-to, breaking back to 2-2, and again for a 5-3 lead when she sprinted to reach a drop shot and swatted a cross-court backhand winner.

"She just elevates her game when she needs to," Bartoli said. "She's not obviously trying to play the hardest on every point."

Bartoli is a tad, well, quirky. Consider: This is the woman who explained that she was able to stun Henin in the Wimbledon semifinals because James Bond portrayer Pierce Brosnan was sitting in the stands.

She hits two-fisted forehands and backhands, and her father-slash-coach, a doctor by trade, devises all sorts of original training methods, including taping tennis balls to the heels of her shoes so she's forced to stay on her toes.

That helped develop her unusual service motion, which actually doesn't involve much motion at all -- Bartoli stands on her tippy-toes, feet together, and doesn't bounce the ball even once before tossing it.

It apparently works, though not nearly as well as Serena's more orthodox serve, which produced 10 aces Sunday, including at 120 mph and 113 mph on the final two points, while her father clicked away with his camera.

"When you play against somebody who serves like this, it's really hard to win the match," Bartoli said. "It's coming really fast."

Not as fast as Venus' serves, which reached 126 mph against the No. 5 Ivanovic.

Venus also started somewhat slowly Sunday, facing three break points in her opening service game. But she saved all three, and never faced another, while dominating baseline exchanges by pushing her 6-foot-1 frame all over the place as her kid sister watched in the stands.

"Obviously I want nothing but the best for her, and she wants nothing but the best for me -- unless, of course, we're playing each other," Serena said. "Then it's like, 'OK, I want to win.' That's how we look at it."