FLUSHING MEADOWS, N.Y. —It was a match between two former No. 1 players, each seeking her third U.S. Open championship.
It was also a match between a 30-year-old and the mother of a 2-year-old.
Friday's U.S. Open semifinal between third-seeded Venus Williams and defending champion Kim Clijsters showcased the power of women's tennis as well as its costly bouts of nerves, with dramatic swings of momentum over 2 hours 23 minutes before a rapt audience at Arthur Ashe Stadium.
Its only shortcoming is that it wasn't the women's final of the U.S. Open, which hasn't seen a closely contested, three-set match since 1995, when Steffi Graf beat Monica Seles.
On Friday, it was Clijsters who prevailed 4-6, 7-6 (7-2), 6-4, by playing gritty defense and capitalizing on Williams's erratic serving at critical junctures to earn a spot in tonight's final.
Clijsters, the No. 2 seed, will face seventh-seeded Vera Zvonareva, who upset the 2009 finalist and No. 1 seed Caroline Wozniacki 6-4, 6-3, earlier in the day.
Clijsters holds a 5-2 edge in her previous meetings with Zvonareva, who also reached the Wimbledon final in July, falling to Serena Williams in straight sets.
Clijsters vs. Zvonareva is hardly the marquee matchup CBS executives had in mind when they proposed moving the U.S. Open women's final to prime-time Saturday night a decade ago. At that time, Venus and Serena dominated the sport and seemed likely to do so for some time.
This year's U.S. Open women's field was denied a good bit of its luster the moment Serena, currently ranked No. 1 in the world, withdrew to recover from foot surgery in July.
And Venus's prospects were in question from the start given that she hadn't competed in two months, taking an eight-week break after Wimbledon to rest her chronically ailing left knee.
She did remarkably well to reach the tournament's final four, and did so without losing a set.
But after a strong start, Williams lost her bearings on her serve amid yet another day of gusting winds, double-faulting twice in a calamitous second-set tiebreak.
Afterward, she conceded that the pressure of the tiebreak was a factor, as well as the wind and her hiatus from competition this summer.
"Obviously I didn't have as much time to train as many of the others," said Williams, who committed 50 unforced errors to Clijsters's 43. "I started out really slow, just an hour a day. I had a good 10 days of practice before this event. I just wish I could have played the bigger points a little better."
After splitting the first two sets, Williams and Clijsters traded service breaks in an edgy third set.
The score knotted at 4-4, Clijsters got the go-ahead break on a perfectly struck topspin lob after Williams charged the net and struck a volley that, for a moment, looked to be sailing well beyond the baseline. But it dropped in, and Clijsters flicked it over Williams's 6-foot-1 frame. Williams, one of the game's more explosive movers, spun and raced toward the baseline but couldn't retrieve it.
In Friday's earlier semifinal, Wozniacki, 20, was frequently a step slow against Zvonareva, who got an early break and closed the first set with ease on an authoritative volley.
Wozniacki's normally reliable forehand broke down as the match unfolded and quickly slipped away in 85 minutes.
"I was really trying," Wozniacki said. "I was really trying to move my legs even more, trying to get into this rhythm where I could lead in this game. But, you know, she was really strong today and she played really well."
Today's action at the U.S. Open will start with the first of the two men's semifinals: top seed Rafael Nadal taking on 12th-seeded Mikhail Youzhny of Russia. That will be followed by five-time U.S. Open champion Roger Federer vs. Serbia's Novak Djokovic.