NEW YORK -- No one has come close to testing Serena Williams at the U.S. Open. Here's how older sister Venus responded to her first challenge: She dug in, pulled out a three-set victory, then went right out and practiced.

	Sporting her lycra cat-suit, Serena Williams made quick work of Daniela Hantuchova.

Both moved closer to another all-Williams final with victories Tuesday, though in vastly different ways.

Serena reached the semifinals by dominating Daniela Hantuchova 6-2, 6-2 at night. Venus had plenty of problems against Chanda Rubin before emerging with a 6-2, 4-6, 7-5 victory to reach the quarterfinals for the 18th time in 20 Grand Slam events.

Top-seeded Serena, the 1999 Open champion, had 29 winners to six for the 11th-seeded Hantuchova, and whipped 12 aces at up to 115 mph. When Hantuchova arrived at the National Tennis Center hours before the match, she was wearing heavy wrapping on her right thumb, injured Sunday night during her fourth-round match against Justine Henin.

''I feel I have nothing to lose. I don't know why,'' Serena said. ''I feel so free and floating, so carefree.''

Next up as she tries to become the first woman since Steffi Graf to win three straight majors: Lindsay Davenport, a hard hitter many think has the best chance of coming between the sisters and a longer string of major titles.

What will Serena wear?

Serena Williams is staying tight-lipped over which controversial outfit she is planning to wear for her U.S. Open semifinal against Lindsay Davenport on Thursday. The Wimbledon and French Open champion has wowed fans at Flushing Meadows this year with two outlandish combinations -- a skin-tight, black, short-legged lycra cat-suit and a shocking pink ensemble she calls "strawberry ice". On Tuesday she was back in black for her 6-2, 6-2 victory over Daniela Hantuchova, but won't say which it will be for the Davenport clash. "Today I was running fast and jumping high... like a cat," she grinned. "That was good. "But I don't know... maybe on Thursday I will be a Pink Panther." -- Reuters

''We're the same style of players. I actually like playing Lindsay. I can't wait,'' Serena said. ''Win, lose or draw, I'm going to have fun.''

Serena has lost a total of 14 games through her five matches so far, spending an average of 51 minutes on court. She certainly seems on pace for another all-in-the-family championship match, having lost to Venus in last year's U.S. Open final and beaten her at the French Open and Wimbledon in 2002.

Venus, meanwhile, lost seven more games against Rubin than she had in her previous three matches combined.

''Today just wasn't my best day,'' Venus said. ''I had a lot of short balls that I just missed. It was definitely strange missing those shots, but I tried to stay calm.''

She'll play Monica Seles for a semifinal berth. Still grunting on each shot and still hitting with two hands off both wings, Seles beat Martina Hingis 6-4, 6-2 to end Hingis' streak of six straight semifinal appearances at the year's final major. Hingis had ankle surgery in May and made it into the field here as a wild-card entry.

On the other half of the draw, 1998 champion Davenport moved into the semifinals by eliminating unseeded Elena Bovina 3-6, 6-0, 6-2. Davenport, playing just her fifth tournament since right knee surgery performed by the same doctor who rebuilt Rubin's left knee, capitalized on Bovina's 36 unforced errors.

Against Rubin, Venus bailed herself out with the help of 41 winners and seven aces, snapping one at 121 mph. But she also made 41 errors, had six double faults, had her serve broken five times, and allowed her 25-set winning streak at the Open to end.

Watching from the stands while snapping pictures through a 2½-foot lens, the Williams sisters' father, Richard, wasn't pleased.

''It looks like all her techniques are breaking down,'' he said.

When the match ended, Venus walked off court and swung her racket in a forehand motion while looking at her father, as though to say, ''I know, I know. We have some work to do.'' Sure enough, 20 minutes later, she was on an adjacent practice court, hitting while getting instructions from Richard.

They might have been going over what went wrong when she was broken three straight times in the second set.

Or what led to the trouble at 5-5 in the last set, with Williams facing two break points. But the 14th-seeded Rubin, who's had two operations on her left knee since January 2001 and appeared to be gasping for air after longer rallies, finally succumbed to Williams' constant pressure.

Rubin sent a forehand wide on the first break point, then put another forehand into the net to close a 17-stroke rally. She threw her head back, sighed, and staggered along the baseline.

''I gave myself a chance in the match. As a competitor, you want to go out in every match and do that,'' Rubin said. ''But it's disappointing not to win it when the chances were there. You look up -- you're right there for the match.''

Of Rubin's seven main draw losses in 2002, five came against players who have been ranked No. 1: the Williams sisters, Davenport, and Seles.

Hingis also used to be at the top, but the last of her five Grand Slam titles came at the 1999 Australian Open. Since then, she's lost in five major finals, while the Williams sisters have combined to win seven of the past 12.

Now Hingis is coming back from ligament damage that one of her doctors said might end her career, and she didn't do much to push Seles off her game Tuesday.

Seles figures to get a different test against Venus Williams, who has won seven of their eight meetings, including in the French Open quarterfinals.

It's been 10 years since Seles won her second straight U.S. Open title, and she talked Tuesday about how the game has changed.

''The girls started to get bigger, stronger, faster,'' the 28-year-old Seles said. ''You see the girls now are 6 feet tall, have a 100 mph serve -- that's the lowest.''

Hmmm, sounds a lot like her next opponent. And Davenport's.