NEW YORK • Whether it's starting a family or starting a business, Kim Clijsters and Venus Williams have figured out how to make life about more than hitting a fuzzy yellow ball.

In the featured semifinal at the U.S. Open today, Clijsters tries to stay on track for her second straight title after a 2½-year layoff during which she got married and had a baby girl.

The 27-year-old Belgian is trying to become the first woman to go back-to-back at Flushing Meadows since Williams did it in 2000-01.

No woman has had a nine-year gap between titles at the U.S. Open. The fact that Williams has a chance could be proof that diversification in life — she's been both praised and criticized for business interests that keep her away from the court — has kept the seven-time major winner fresh at the "old" age of 30.

There have been injuries mixed in there, including a twisted left kneecap that kept her from practicing in the lead-up to this year's U.S. Open.

"I think obviously the way that she's been playing and the way that she has mentally looked, I think it's maybe even been good for her to have been away for that long," Clijsters said. "Because she looks more hungry than ever."

Their lifetime series is tied at 6-6, and Clijsters is 2-0 since her comeback, including a 6-0, 0-6, 6-4 win over Williams in the fourth round in New York last year.

The winner of No. 2 Clijsters vs. No. 3 Williams will play for the title against No. 1 Caroline Wozniacki or No. 7 Vera Zvonareva. Zvonareva is trying to make her second Grand Slam final of the year, while Wozniacki is going for a repeat trip to the final at Flushing, where she lost to Clijsters last year.

Wozniacki, a 20-year-old from Denmark, got the first seed when Williams' sister, Serena, was forced to withdraw because of an injury. She has more than answered any questions about her worthiness as the top seed, not dropping a set in her first five matches.

She's been called a "wall" and a "backboard." Pressured by her unrelenting ability to get balls back, Wozniacki's opponents have averaged 33 unforced errors.

She "retrieves a lot of balls," said Maria Sharapova, who lost to Wozniacki in the fourth round. And then, Sharapova said, "When she had the opportunity to step in, she took it and went for her shots."