Here's who can stop Maria Sharapova

Maria Sharapova has traveled a long, long way from a hospital gurney following her shoulder surgery in October of 2008 to the title she earned in Rome on Sunday. But even her most ardent supporters might have been hard put to guess that she would emerge as the closest thing the WTA has to the ATP's "king of clay," Rafael Nadal.

After Sharapova's queenly, if gritty, performance on the rain-drenched court in Rome, where she survived a three-hour match -- plus a two-hour rain delay -- against Li Na, she has to be the on-paper favorite to win the French Open.

Or does she?

Sure, Sharapova now has won two of the three biggest tournaments on the trail to Roland Garros (Stuttgart and Rome). But there's one massive storm cloud still on her horizon as we approach the grand finale of this long Euro-clay swing: Serena Williams.

Serena's fans will quickly note that their heroine bypassed Stuttgart and then waxed the No. 2 Sharapova but good -- again -- in the quarterfinals just the other week in Madrid. That win lifted Serena's head-to-head with Sharapova to 8-2, without the loss of a set in their past two meetings. For good measure, Serena then bumped off No. 1 Victoria Azarenka for that title.

It looked like Maria might get one more chance to figure out No. 6 (with a bullet) Serena. They were on track to meet in the final of Rome, but Serena pulled out before her semifinal against Li, citing a back injury. No matter how much Serena's back hurts, it's probably not as much as the ache in Sharapova's mind when she looks at their recent history -- and what it may portend for the French Open.

But Sharapova will have one big, if not exactly guaranteed, source of solace rolling into Paris, and that's Serena's history of struggle in that cathedral of red clay. Serena has not been beyond the quarterfinals at Roland Garros since 2003, the year after she won her lone title at that major. That's a long time, with a lot of bad karma to overcome.

By contrast, Sharapova was a semifinalist last year (l. to Li) and a semifinalist on '07 as well (l. Ivanovic). And she has to be feeling pretty good about her game -- at least on the days when she's dialed in.

Sharapova takes a lot of what you would have to call bad losses, no doubt about it. Two of the most recent were inflicted by Serena. But it's also clear by now that one of Maria's outstanding talents is the ability to wipe those blowouts off her hard drive.

This is the woman who lost the Australian Open final early this year to Azarenka, 6-3, 6-0 and then dropped the Indian Wells final to the Belarusian in straights sets as well. But Sharapova turned the tables in the Stuttgart final, allowing the No. 1 player just five games in a 6-1, 6-4 pasting.

This relentlessness in Sharapova, this unwillingness to be denied combined with a facility for living in the future is an admirable trait. You can see it in the way she's evolved from a player who seemed to have no chance on clay, what with her powerful but stiff athleticism, limited repertoire of shots and disinterest in long rallies, into a woman who's learned that the secret to success on that surface lies more in imposing your game than altering it to suit the pace.

Given how well Maria and Serena have been playing, it's possible that they'll meet as early as in the quarterfinals. But bear in mind that Serena just hasn't been a commanding figure in Paris in a long, long time. Sharapova will take some comfort and confidence from that and how much it will help her is an open question.

Maria may be the queen of clay for now, but Serena is here to remind us of those sagacious words penned by Shakespeare: "Uneasy lies the head that wears a crown."