It was just like old times Wednesday.
The two are still favored to meet in the French Open final for a fourth straight year. There's little predictability, meanwhile, among the women.
Here are five burning questions leading into the heart of the clay-court season.
How do you stop Rafa?
The only thing that can stop Nadal on clay is an inspired opponent who is given divine help or injury, or a combination of the two. Otherwise a fifth straight title at Roland Garros is inevitable.
Who, however, really thinks he can top Nadal on dirt? When was the last time we saw him vulnerable?
Seldom would "nervous" and "frightened" be used to describe the bullish Nadal's state of mind during a clay-court tussle -- or any bout, for that matter -- but the Spaniard admittedly got a little anxious at the French Open three years ago when a piece of banana became wedged in his throat.
Nadal was so panicked he breached tennis etiquette by stopping midgame versus French favorite Paul-Henri Mathieu in the midst of a five-hour thriller, drawing jeers from the moody Parisian crowd.
"I was now paying more attention to my throat than to tennis," Nadal said at the time.
David Nalbandian? Maybe. Tellingly, Nadal revealed he had no idea how to play the crusty Argentinean at Indian Wells last month, and only by bypassing five match points did he survive. Nalbandian hasn't surpassed the fourth round of a major since the French Open in 2006 (yes, it's been that long), so getting a shot against Nadal seems unlikely.
Clay certainly isn't Andy Murray's most productive surface, though the Scot rarely suffers from an inferiority complex. In his corner once more for the clay-court season is Nadal's buddy, two-time French Open finalist Alex Corretja.
"The guy who's shown an incredible amount of belief is Murray," said veteran coach David Felgate, who has worked with the likes of Tim Henman, Xavier Malisse and Nicole Vaidisova. "I wouldn't be surprised if deep down he thinks he's got a shot, a way or a plan, because he's a great thinker and strategist."
Does more misery await Mr. Newlywed?
The short answer is yes. In his first clay event of the year, Federer uninspiringly succumbed to Swiss compatriot Stanislas Wawrinka in Monte Carlo. So much for the welcomed dirt season after a long, gloomy run on the hard courts.
This was after Federer swallowed his pride and asked for a wild card into this week's Monte Carlo Masters, surely prompting organizers to pop a bottle of champagne or two. As it turned out, last week's stop in Casablanca might have been a better option: If he and Mirka had pushed up their wedding, an exotic working honeymoon in North Africa would have followed. Imagine dining on those tagines snuggled up to the Atlantic.
Though Federer has slipped to third in the depth charts behind Nadal and Murray on the hard stuff, he's still the second-best clay-courter (right?). And since no one truly expects him to triumph at Roland Garros, the pressure eases. The increasingly emotional Federer gets to recover a tad and probably notch more victories (i.e., get to the finals) heading into Wimbledon, where he's itching to return to the top.
But it remains to be seen if Monte Carlo is a harbinger of things to come, or of the Mighty Fed just wasn't prepared to meet the clay demands.
Not so uplifting are Federer's recent final-set meltdowns against Nadal, Murray and Novak Djokovic, which have been more damaging than 2008's headline-grabbing defeats to Andy Roddick and Mardy Fish in Miami and Indian Wells, respectively.
"I don't think the guys walk on court now thinking they have no chance against him," said former French Open quarterfinalist Jimmy Arias, now a commentator for ESPN International. "That's something he'll have to overcome. Once you get that aura, it wins you some matches on its own, so if he did have a bad day, guys would maybe get tight when they had a chance. He could seemingly get that back if he could turn it around, but at this point it's vulnerable. He makes mistakes at big moments."
Can Serena conquer Paris?
If you can't beat 'em, join 'em, or something like that.
Undaunted, Williams recently bought an apartment in lovely Paree and even conversed in francais while participating at Paris' Open GDF SUEZ in February.
Is she gearing up for the winner's speech this June on Court Philippe Chatrier?
The French Open is the lone major Williams hasn't won more than once. Her solitary title came in 2002, the birth of the Serena Slam.
Making Williams hit that extra ball on clay often leads to errors, which was witnessed in an ugly third-round loss to pesky Slovenian Katarina Srebotnik last May. The day got even uglier for the Williams clan when Venus Williams fell to Italian Flavia Pennetta.
Williams dropped her 2009 clay-court opener to a journeywoman in Marbella, Spain, last week.
"Don't read anything into that loss," Felgate said. "Generalization, in the women's game, I think it's less about the run-up to Paris, especially for the Williams sisters. Does Serena come fit and ready to play for Paris? That's important."
The recent slides of Elena Dementieva and new No. 1 Dinara Safina, albeit on hard courts, won't hurt. And Ana Ivanovic still can't find any consistency since claiming an inaugural Grand Slam title at the French Open in 2008.
Jelena Jankovic, though, is due for a revival, and clay is her best surface. Winning in Marbella was a nice start.
Will the dirt be kind to U.S. men?
Who knows, following an interesting week in Houston.
James Blake's downward spell continued: The top seed, he was a first-round loser to wily Argentine Guillermo Canas. Not to be outdone, good pal and second seed Mardy Fish exited to Bjorn Phau. "I've played against plenty of guys, and he gets to balls that nobody else can get to," Fish said of the pint-sized German -- who has never exceeded 59th in the rankings.
Thankfully for organizers, a former No. 1, Lleyton Hewitt, reached the final and faced an American, Wayne Odesnik. Odesnik, born in South Africa, actually likes clay and has spent time training in Spain. His efforts in Texas boosted his ranking to 77th, a career best. John Isner's resurgence persisted with a quarterfinal placing.
Roddick, who is tying the knot with swimsuit-model fiancée Brooklyn Decker this weekend, is shunning the infancy of the European clay-court campaign. He remains the United States' biggest threat on the dirt, though. (Yes, Robby Ginepri, recovering from appendix surgery, got to Round 4 at the French Open in his most recent visit.)
"There are more floater clay-court guys, so obviously Andy's more vulnerable. But with a somewhat favorable draw and a bit of confidence this year that he seems to have, there's no reason why he can't make it to the second week," Arias said.
An injured Roddick skipped the French in 2008 and hasn't reached the third round since his maiden appearance in 2001. Then there's Sam Querrey, ruled out of Houston due to an ailing hamstring. Querrey memorably advanced to the quarters in Monte Carlo last year and gave Nadal a run for his money, on clay, in September's Davis Cup semifinals.
Who are some of the floaters?
Clay produces dangerous dark-horse specialists like no other surface. Carla Suarez Navarro's stock keeps rising. The delightful 20-year-old Spaniard with the similarly delightful one-handed backhand -- Venus Williams saw plenty of it in Melbourne -- stretched Jankovic to three sets in the Marbella final, less than a year after sprinting to the French Open quarterfinals as a qualifier.
Hard to believe, but Suarez Navarro's compatriot, former world No. 1 and 2003 French Open champ Juan Carlos Ferrero, won his first title in six years on Sunday in Casablanca. Ferrero, still under 30, entered the event ranked outside the top 100 due to an array of injuries.
The list is sure to grow as the season blooms.
Ravi Ubha is a frequent contributor to ESPN.com.