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.

As for that tennis part — well, things are going pretty well there, too.

In the featured semifinal at the U.S. Open on Friday, 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, Jada.

Not a bad second act.

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 in 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, as well, 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 been even been good for her to have been away for that long," Clijsters said. "Because she looks more hungry than ever."

The winner of No. 2 Clijsters vs. No. 3 Williams will play for the title against either 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 of 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."

Aggressive play, of course, has been the trademark of the Williams sisters for years. As top players tried to catch up to stay competitive, women's tennis turned into a power game, and when Clijsters returned after her break, she was greeted by a different style of play — but one she adjusted to rather quickly.

Her trip to last year's U.S. Open was designed mainly as a tuneup, the thought went, so that when she began her comeback in earnest in 2010, she'd know what to expect. Next thing she knew, she was in the middle of a championship celebration at center court, scooping the trophy in one hand, her daughter in the other. Her 6-0, 0-6, 6-4 win over Venus Williams in the fourth round may have been the first, best sign that Clijsters had a legitimate chance.

"Just the ability to compete," Williams said when asked what impressed her most about Clijsters. "I think in coming back from her layoff, I think she never lost that. Obviously, she's a very good athlete. When you're a really, really incredible athlete, it really takes your game to another level. So definitely it takes some special kind of God-given talent."

Their lifetime series is tied at 6-6 and Clijsters is 2-0 since her comeback, including the win here last year.

Clijsters has earned more than $17 million in prize money over a career that began in 1997. Williams' lifetime earnings are at more than $27 million.

For Williams, it's great seed money to start her own interior design company, V Starr Interiors, join her sister in buying a piece of the Miami Dolphins and start her own fashion line. The tennis dresses she designed for the U.S. Open are a tribute to New York. All have sequins on material that looks like velvet, and every day, Venus comes out in a different colored dress.

She designed seven of them, which happens to be the number of matches it takes to win the whole thing.

Will she get to wear them all?

"Well, I want to be in the final, because then obviously it's just one more step," Williams said. "But I'm just focused on the semis, and I don't get too excited unless the tournament is over."