-- As preambles go, the first week of women's tennis at the U.S. Open was flat and lifeless. Rather than foreshadow any drama to come, the daily routs -- with favorites such as Maria Sharapova, Kim Clijsters and Lindsay Davenport steamrolling past overmatched opponents in less than an hour's time -- only highlighted the vast competitive gulf between the game's top women and all the rest, who shrieked, grunted and flailed at balls to no avail.

But with the field of 128 finally winnowed to four, a soap opera couldn't have supplied more drama than the pair of women's semifinals staged Friday at the National Tennis Center. Rackets got slammed, charges of gamesmanship flew, profanities were spat and tears were choked back.

And the result set up a prime-time women's final Saturday that pits the 22-year-old Clijsters, who has never won a Grand Slam event, against 30-year-old Mary Pierce, who won her first major a decade ago and her last in 2000.

The 12th-seeded Pierce was first to secure her spot in the finals, rebounding from a miserable first set to upset last year's U.S. Open finalist, Russia's Elena Dementieva, 3-6, 6-2, 6-2. Pierce becomes the tournament's oldest female finalist since Martina Navratilova in 1991, who was 34 at the time of her straight-set loss to Monica Seles. But the manner in which Pierce engineered her comeback -- delaying the match 12 minutes to receive treatment for suspect ailments -- will be debated long after her shot-making is forgotten.

Clijsters, seeded fourth, earned her spot in a more traditional manner -- the hard way -- needing six match points to defeat the top-seeded Sharapova, whose will to win nearly compensated for her sloppy play. Clijsters dominated the opening set, but Sharapova roared back before Clijsters prevailed, 2-6, 7-6 (7-4), 6-3.

In weathering Sharapova's defiant barrage of winners, Clijsters took another step toward shedding her reputation for choking when the stakes are high. Her reward is a fifth opportunity to win the major title that has eluded her. Clijsters is 0 and 4 in major finals.

Having announced last month she intends to retire in two years, Clijsters is approaching the quest with heightened urgency. It's not that she no longer enjoys the game. If anything, she savors it more after missing most of 2004 after undergoing wrist surgery. It was the latest in a long list of injuries -- the price, Clijsters has learned, for the physical brand of tennis she plays, which has her scrambling, lunging and sliding all over the court to retrieve balls most women couldn't touch. Whether unwilling or unable to adopt a less-punishing approach, Clijsters has made peace with the damage it exacts on her 5-foot-8, 150-pound frame -- at least to a point.

"I'm going to go for it because, you know, it could be over," Clijsters said. "If I get another wrist injury, if I have anything else, my career could be over very soon. That's why I just want to go out there and just enjoy every shot that I can hit."

Like Clijsters, Pierce also knows what it's like to be without the sport she has played since childhood. She tumbled out of the top 200 in 2001 after being sidelined by a back injury. The forced idleness helped her realize that tennis was something she genuinely loved rather than something she had to do to please those around her. With a new outlook, new trainer and new approach, she is playing her best tennis in years.

While Pierce's late-career resurgence makes a compelling tale, her post-match interview was dominated by questions about her injury-related timeout.

The 12-minute pause in play marked a dramatic shift in momentum. The sixth-seeded Dementieva bolted to a fast start, driving deep, angled groundstrokes that a lethargic Pierce couldn't retrieve. Dementieva even managed to get her erratic serve under control, committing just one double fault in the first set.

In a role reversal, Dementieva broke Pierce's serve early. And Pierce committed her third double fault to get broken a second time, handing the set to the Russian, 6-3.

On the changeover Pierce called for the trainer, who wheeled out a portable medicine cabinet and set to work. Pierce complained of two ailments -- soreness in her lower back and a twinge in her right quadriceps. She asked if she was allowed to take both of her allotted medical timeouts at once. Informed she could, that's what she did, leaving Dementieva to jog in place, shadowbox and slip on a jacket in an effort to stay warm.

Meanwhile, Pierce lay prone on the court for a back massage. Then she sat up while her thigh was wrapped. CBS announcers used the gap to criticize the rules that allowed such a lengthy break, rebuke Pierce for exploiting the rules and question whether her ailments were real.

Said four-time U.S. Open champion John McEnroe, "There's some serious mental gamesmanship going on right now."

When play resumed, Dementieva won the first game of the second set but never regained her edge, while Pierce sprinted around the court with the legs of a teenager.

Dementieva conceded that her opponent did nothing outside the rules. "But I don't think it's fun for the players and the crowd just to see her, you know, 12 minutes lying down and do some treatment," Dementieva said.

Also Friday, twins Bob and Mike Bryan won their second title in a Grand Slam event, defeating the world's No. 1 duo of Jonas Bjorkman and Max Mirnyi, 6-1, 6-4. In 2003, the twins won the French Open.

Kim Clijsters, seeking her first major title after four runner-up finishes, celebrates her win over Maria Sharapova.