The upper echelon of women's tennis is no place for the hesitant, the angst-ridden or, increasingly, the short, as Wimbledon's unforgiving grass courts demonstrated Tuesday, producing the semifinalists who will contend for the sport's most coveted title. Three of the four stand 6 feet or taller.

American Lindsay Davenport tops the quartet at 6 feet 21/2 inches. The tournament's top seed and world No. 1, Davenport earned her semifinal spot by defeating Russian Svetlana Kuznetsova, the defending U.S. Open champion, 7-6 (7-1), 6-3, in a quarterfinal match that saw 15 aces and far too many unforced errors (43).

Fellow American Venus Williams, who stands 6-1, advanced in more impressive fashion, overpowering Mary Pierce, 6-0, 7-6 (12-10). With Williams on the opposite side of the draw from Davenport, her victory keeps alive the possibility of an all-American women's final on Saturday.

Williams will face defending champion Maria Sharapova in one semifinal Thursday. The 6-foot Sharapova has yet to drop a set at this year's Wimbledon, though she had her hands full in Tuesday's early going against fellow Russian Nadia Petrova before prevailing, 7-6 (8-6), 6-3.

Thursday's other semifinal will pit Davenport against Frenchwoman Amelie Mauresmo, comparatively undersized at 5-9, who sent off Russia's Anastasia Myskina, 6-3, 6-4, in Tuesday's quickest quarterfinal.

Deployed properly, height is an enormous defensive and offensive weapon on a tennis court, giving strapping players the reach to retrieve balls that shorter players can't, as well as the leverage to channel power into their serves, overheads and groundstrokes. And it's a particular asset on grass, where balls zip past, rallies don't last and big serves carry an extra punch.

Just ask 5-3 Jill Craybas, who managed to win just two games in her fourth-round loss to Venus Williams. "There were a lot of rallies where I felt like it might have been a much more effective shot if she wasn't so long," Craybas said, "but she got to a lot of balls that other players might not have gotten to."

There's a mental component to tennis as well, as every weekend duffer can attest. And the four women who advanced Tuesday did so, at least in part, by carrying their confidence as high as their heads.

At 29, Davenport has never felt better on court, she said, including the stretch in her early 20s when she was regularly winning Grand Slams, claiming the 1998 U.S. Open, 1999 Wimbledon and 2000 Australian Open titles. She attributed her second wind to spending less time drilling balls in practice like an automaton and spending more time in the gym, toning her fitness and confidence.

"There's no question that physically I'm a better athlete," Davenport said, "and I believe I'm a smarter player."

Having slogged through a tough three-setter against Belgium's Kim Clijsters on Monday, Davenport had a ready excuse to be a step slow against the athletic Kuznetsova, who just turned 20, when they walked onto Court No. 1. Davenport showed no sign of fatigue but groped for her rhythm as the players walloped their way through the first set.

Kuznetsova squandered set point at 5-4. It was one more in a succession of critical shots the young Russian has flubbed in the late stages of Grand Slams. So when a tiebreaker was required to settle the set, it was hardly surprising that Davenport, a veteran in her eighth Wimbledon quarterfinal, held on to clinch it, 7-1, while the impetuous Kuznetsova sprayed balls far and wide.

"She does go for quite a lot," Davenport said. "I definitely got a lot of free points out there."

Meanwhile, the 14th-seeded Williams was making her first appearance on Center Court this fortnight. And she wasted no time reminding her audience and Pierce (as well as the tournament's seeding committee) just why she has two Wimbledon titles on her resume.

Williams broke Pierce on her first three service games to race through the first set, 6-0, in 21 minutes. By the time Pierce figured out how to counter Williams's booming forehand, her prospects for advancing to a Wimbledon semifinal for the first time in her 16-year career were on life-support. In the interim, with Williams blasting serves and passing shots to her right and left, a baffled Pierce bought all the time the rulebook would allow, pausing between points to realign the strings of her racket, tidy her blonde ponytail and blow on her fingers as if drying a wedding-day manicure.

The crowd showered Pierce with wild applause when she finally held serve in the second set, cheering her either out of empathy for her public dressing-down or gratitude for her stab at making it a match. And Pierce went on to find a measure of success against the hard-slugging Williams by wrong-footing her whenever possible, luring her to one corner of the court and then blasting the ball to the opposite corner at the last minute. But Williams wasn't snookered often.

Pierce had opportunities to force a third set but failed to convert four set points in the tiebreaker.

"What can I say?" she said later. "I did the best I could. I know that I hesitated a little bit, and I needed to be more aggressive, basically, on a few shots."

Six-foot Maria Sharapova, the defending champion, returns a shot from Nadia Petrova in a 7-6 (8-6), 6-3 victory.Lindsay Davenport, 6-21/2, serves in her 8th career Wimbledon quarterfinal.Venus Williams, 6-1, made quick work of Mary Pierce, beating her, 6-0, 7-6 (12-10), on Center Court to advance to tomorrow's semifinals.