Mary Pierce beat Lindsay Davenport 6-3, 6-2 to advance to her first Major semifinal since 2000. Heinz Kluetmeier/SI

SI.com's Jon Wertheim is covering the French Open for the magazine, and we caught up with him today to get his perspective on the results thus far at Roland Garros.

SI.com: Today was Ladies' Day at the French Open, all four of the women's quarterfinals were played. What was your take on the action?

Wertheim: The day started with two cases of nerves and ended with two fairly steely performances. Ana Ivanovic was a wreck in her match against Nadia Petrova. She looked nothing like the player who had won four matches to get here. I thought she had a real chance, but she sprayed balls, never found her rhythm and, to Petrova's credit, wasn't around long enough to settle into a groove. At the same time -- in a match that must have been hell on telecasters' tongues -- Sesil Karatantcheva had Elena Likhovtseva on the ropes but couldn't finish her off, losing 6-4 in the third set. Some players relish the big match; others retreat from it. Both Ivanovic and Karatantcheva are young players with bright futures. Hopefully next time, they'll be more mentally prepared.

In the other two matches, Justine Henin-Hardenne played a terrific match against Maria Sharapova, and Mary Pierce beat a decidedly "off" Lindsay Davenport.

SI.com: With Davenport falling, there are now no Americans left. Do you think Americans are psyched-out by clay?

Wertheim: In fairness to Davenport, this was her best performance in Paris since 1999. But, boy, this situation has gotten ugly. To make matters worse, Jessica Kirkland -- an American who was the top seed in the girls draw -- lost today in three sets. So did Donald Young, the highly regarded 15-year-old American. Tennis Australia recently sent a group of prospects to Barcelona for clay-court tennis boot camp -- maybe the USTA needs to do the same thing. It's becoming more and more essential for players to compete on clay. And yet the Americans are doing worse and worse.

A lot of the problem is attitude. Not just getting unnerved by the surface -- the bounces and sliding and power blunting -- but by the type of tennis it forces you to play. Clay-court tennis takes patience and real point construction. When you've been worshipping at the altar of brute force, the adjustment can be significant.

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SI.com: Henin-Hardenne had a relatively easy time today, beating Sharapova in straight sets. Did that result surprise you?

Wertheim: Mentally, Henin-Hardenne has been "nails," as tennis players say. On Monday, she staved off two match points to win. Today, she picked apart Sharapova. She played a smart match, made the long-legged Sharapova play a lot of low balls. Henin-Hardenne served well and didn't miss on the big points. It was a comprehensive defeat, a command performance. Henin-Hardenne may be banged up but as long as she competes this well, it's hard to see anyone beating her.

SI.com: What about the men?

Wertheim: Well, now we have the semifinal we've all been clamoring for: Roger Federer versus Rafael Nadal. Before the tournament, the thinking was this was the de facto final. After all the upsets on the lower half of the draw that certainly appears to be the case now. Federer made fast work of Victor Hanescu, a nice player but not someone who's going to threaten the top seed. Nadal had a tougher match against fellow Spaniard David Ferrer. This was close at first. Then Ferrer had a few set points, Nadal hit some ridiculous winners under pressure, and it completely changed the match. We hear about Nadal's speed and his forehand and his lefty look (not to mention his outfits), but he also competes better than anyone on the Tour. He goes for the kill when he's leading, and he conjures his best tennis when he's down. And he doesn't lapse much in the middle. This semifinal against Federer ought to be terrific.

SI.com: What about tomorrow's matches, the two men's quarterfinals?

Wertheim: Um ...You know Jeff Foxworthy has that riff "Chances are you're a redneck if ..."? Well, chances are you're a hard-core tennis fan if you get jazzed about Guillermo Canas, Mariano Puerta, Tommy Robredo and Nikolay Davydenko. They're all nice players -- and all credit to them for getting to this stage -- but as second-week Grand Slam matchups go, those are pretty shaky ... even on clay. I'm guessing the television ratings, at least outside Buenos Aires, are not going to be particularly strong. I would give Canas the edge against his fellow Argentine Puerta. Puerta has been a machine, but Canas is the better player. And assuming Robredo doesn't come off his high from beating Marat Safin on Monday, he stands a good chance of getting through. But like a wise man once said: "Sometimes you get Nadal-Federer. Sometimes you get Canas-Robredo. Especially when there's clay underfoot, that's the way the éclair crumbles."