In a loopy run-up to the French Open and Wimbledon, No. 1 Roger Federer and No. 2 Rafael Nadal played an exhibition on a half-grass (Federer's favorite) and half-clay (Nadal's specialty) surface. Advantage ... Nadal?

	Even in a match played for fun and a reported 50-50 split of the pot, Nadal got the best of Federer. Bob Martin/SI

Technically it didn't count. So Rafael Nadal didn't extend his winning streak of 72 consecutive matches on clay courts. Nor, for that matter, did he snap Roger Federer's streak of 48 straight victories on grass. But Nadal's 7-5, 4-6, 7-6 triumph over Federer in a May 2 exhibition titled The Battle of Surfaces may have provided a trailer of sorts to tennis's feature presentations this summer.

Held on the Spanish island of Mallorca, where Nadal was raised and still lives, this unsanctioned event pitted the ATP's top two players against each other on a hybrid court, half clay and half grass. Since Nadal and Federer met in the finals of the French Open and Wimbledon in 2006 -- Nadal won the former, Federer the latter -- organizers figured the timing was ideal. (The French Open begins on May 27; Wimbledon, June 25.) Adding to the intrigue, Nadal is ranked No. 2 but has a 7-3 record against Federer, and his clay-court expertise is the biggest threat to Federer's quest to win the Grand Slam. (Federer won the first major of the year, the Australian Open, in January.) As the promotional material breathlessly put it, "We are in a position to reveal the mystery by measuring the forces of Federer and Nadal, the kings of grass and clay." Gimmicky? Absolutely. But apart from selling out the 7,000-seat Palma Arena, the event drew more interest than any tennis exhibition since Billie Jean King played Bobby Riggs in the Astrodome 34 years ago.

In a raucous atmosphere resembling a bullfight's, the players gave an honest accounting of themselves. They even switched footwear on each changeover to accommodate the different surfaces. As many predicted, the player with clay underfoot usually had the edge, as his shots and serves skidded off the grass -- installed the night before the match, after the original turf, imported from Bordeaux, became infested with worms -- while the pace-blunting clay gave him ample time to set up.

Notwithstanding the million euros ($1.3 million) they allegedly split, it's puzzling that Federer and Nadal agreed to take part in this peculiarity. It was akin to, say, the Bears and the Colts playing a flag-football game a few nights before the Super Bowl. The cynic might suggest that perhaps this was a way for Federer -- who often seems unhinged by Nadal's fist-pumping intensity -- to dial down the volume of the rivalry. "I like the fact that the stadium is located in Mallorca, Rafa's home," Federer said before the match. "He has been to Basel [Federer's hometown in Switzerland, site of an ATP tour stop each October], and now I have the opportunity to play at his place." Perhaps Nadal saw a chance to make a statement before the heart of the Grand Slam season. Maybe they were simply seduced by the novelty of it all. Nadal stressed the "fun" of this "unique experience."

Regardless, it was telling that Nadal was the player who conjured the winning shots in the third-set tiebreaker. The predictive value of this "battle" is surely limited, but it was yet another example of the Spaniard's unmatched competitive resolve. The principals downplayed the outcome, but with the French Open looming, neither will completely discount the match. The significance of this exhibition goes, you might say, beyond the surface.