What's going on in Upset City?

— -- PARIS -- OK, this is getting way out of hand.

It was shocking when No. 2 seed Li Na crashed out in the first round at the hands of a Frenchwoman named Kristina Mladenovic, but upsets happen. Then No. 1 seed Serena Williams left the building at the hands of Garbine Muguruza. It was surprising, but Serena has a spotty history at the French Open.

But after Friday's stunner on Court Philippe Chatrier, the conspiracy theorists are going to have a field day. Ajla Tomljanovic wrecked an oddly anemic No. 3 seed Agnieszka Radwanska 6-4, 6-4.

This is the first time in the Open era that the top three women's seeds failed to reach the fourth round of any Grand Slam. Take a deep breath and drink that statistic in. In the 46 years of open tennis -- nearly half a century -- there's never been this kind of anarchy on the women's side heading into the second week of a Slam.

Throw in the absence of world No. 5 Victoria Azarenka (foot injury) and the Friday elimination of former Roland Garros semifinalist Dominika Cibulkova, the No. 9 seed, and you have a very depleted draw. Or, if you are still in it, an appealing path, full of possibility, to a Grand Slam singles title.

ESPN.com tennis editor Matt Wilansky and senior writer Greg Garber break it down in the latest Baseline Buzz:

Garber: I don't think these are isolated incidents. There's something larger going on here. Consider the three players who crafted these upsets:

• Muguruza, age 20, ranked No. 35

• Mladenovic, age 21, ranked No. 103

• Tomljanovic, age 21, ranked No. 72

Both Mladenovic and Tomljanovic celebrated their 21st birthdays earlier this month, which means this trio is just arriving on the grand stage. Williams and Li Na, both 32, are on the downside of their careers, and Radwanska, 25, is only a few years away.

"After seeing the two first seeds go out, you kind of feel like 'I can do this, too,' " Tomljanovic said afterward. "I grew up with these girls that are beating them. I went out there, and I really, inside, really thought I could win. I think that showed and it is why I won."

Wilansky: I think it goes without saying Generation Y might (finally) see an opening. Look at it this way: The Aussie Open finalists -- both gone. Last year's US Open finalists (Serena, Victoria Azarenka) could be anywhere -- just not at Roland Garros. And the Wimbledon finalists ( Marion Bartoli, Sabine Lisicki) are nowhere in sight. In other words, all the trophy winners from the previous three Slams have either lost, retired or just never showed up. It goes without saying that after a brief window of stability in the WTA, the tour is a complete mystery.

It's also safe to say the women who knocked off the top three seeds are virtually unknown to the casual tennis fan. Look at their previous best wins: Muguruza's was over a world No. 8, Mladenovic over a No. 9 and Tomljanovic had never beaten anyone ranked higher than No. 26. In other words, the quality of opponents they've taken down here in Paris is much higher than anything they've done in the past.

Garber: Maria Sharapova might want to consider heading over to Notre Dame and lighting a candle or two. Perhaps a few Louis Vuitton bags for Muguruza and Tomljanovic? Might I suggest the Speedy 35? Only 850 Euros, monogram included. Because her ranking has fallen, Sharapova would have played Serena in the quarterfinals. And when your head-to-head record is 2-16 against someone, it's always nice when someone else does your dirty work. And now that Radwanska is out the picture, No. 8 seed Angelique Kerber and No. 14 Carla Suarez Navarro are the worst-case scenario in the semifinals. Talk about a soft draw.

These crazy kids are so young, they don't really understand what they're doing. Look at the unseeded Tomljanovic's run. She beat 2010 French Open champion Francesca Schiavone in the first round, No. 32 seed Elena Vesnina in the second and now the No. 3 Radwanska. Serena and Li Na, particularly, have been defying the gravity of age for a few years now. These upsets suggest that possibly their time has come ... and gone.

Wilansky: Possibly, but that certain someone vowed to do whatever it takes to "never lose again," which means we might be writing a different story when Wimbledon is said and done. A story we've already written 17 times, give or take.

But if Sharapova does bestow Tomljanovic and Muguruza with those swanky little gifts, as you suggested, she may want to consider sharing them with Chris Evert. Tomljanovic, a student of the 18-time Grand Slam winner's academy, said, "I'm very fortunate to have [Evert] in my corner. Not only she helps me on the court, but we actually have a great relationship off the court. We get together when I'm in Boca. And, you know, she calls, I call her, she calls me."

Well, of course, otherwise that would be rude. But I wonder if Tomljanovic & Co. have staying power or if this is another brief interlude by players whom we won't be talking about in two weeks. Still, Tomljanovic has systematically progressed in her brief career. Last year at Wimbledon, she fell in the first round and then won a single match in both Flushing and Melbourne. And now, she's on to the fourth round.

Garber: That would make her -- what? -- 3-0 for her career at Roland Garros. Undefeated. Perfect. Even Rafael Nadal (61-1) can't say that.

Here's an interesting nugget, culled from the WTA match notes: The last time Radwanska lost to an opponent ranked outside the top 50 was against No. 64 Simona Halep at last year's tournament in Rome. In almost exactly a year, Halep has soared into the ranks of the elite. After Serena, she has the second-best winning percentage among WTA players. And, at 22, she's a decade younger.

That sound Serena & Co. are hearing is the footsteps of their successors. And suddenly, it's getting louder.

Wilansky: Well, not so fast. The sound you might be hearing is that of the victims' awkward, heavy footsteps. I spoke to Evert earlier, who explained why an overhaul atop the game is a stretch. "When you reach a certain point in your career," she said, "you have to understand you are not going to be fresh getting out of bed every day to practice or to play a match. And this is what's happening. We've seen it with Roger [Federer], Martina [Navratilova], myself and even Andre [Agassi] at the end of his career. You can still play peak tennis, but you're going to have more bad days."

What it really comes down to, more than age, is motivation. As Evert said, Serena began last year jumping around, proclaiming a French Open title was her mission after falling in the quarters of the Aussie. "But this year, I questioned whether Serena could have the same enthusiasm," Evert said. "A 27-year-old can be as good as a 32-year-old depending on how much you play. And in Serena's case, she played and used a lot of energy in the past year.

"But give credit to the other players. The depth of the game, especially Nos. 5-20, is really showing. They're not as intimidated by the top players as they used to be."

Garber: And now these women -- ranked Nos. 35, 72 and 103 -- are smelling the café creme, too.

These are heady times for Tomljanovic. After beating Radwanska, she conducted her biggest interview ever.

"I never had lights in front of me," she said, drawing laughter from the assembled reporters.

Earlier, with a straight face, she talked about the youth movement that is threatening the hierarchy in women's tennis.

"The draw, it has 32 names that have a number next to it," Tomljanovic said. "But really, in my head, it doesn't matter. You respect everyone, but you don't fear anyone.

"Yeah, with the seeds out, I guess we are stepping up a little bit."