By William Finnegan

updated 5:06 p.m. ET April 3, 2008

Men's tennis has been frozen at the top for years. Coming into 2008, 13 of the past 14 Grand Slam tournaments had been won either by Roger Federer or Rafael Nadal. Federer, the most dominant player in the history of the game, had appeared in 10 straight Grand Slam finals. That's like the Yankees appearing in 10 straight World Series — but only if Major League Baseball had 128 teams and every game were an elimination round. Federer has been the world's No. 1 player every week for more than four years; Nadal, who rules the red clay with his colossal left arm, has been the No. 2 for almost three years. Each of these runs is unprecedented — and what's more, nobody else has really been within shouting distance.

Until now. If you haven't yet made his acquaintance, allow me to introduce Novak Djoković. The name first registered with me a couple of years ago, when I'd heard about him publicly declaring his intention to become the world's top player. In the age of Federer, this was rank lèse-majesté — some trash-talking Serbian teenager who obviously didn't understand his place in the universe. Then I saw Djoković play. He was still raw, probably 18, but his gifts were prodigious. He was fast, rangy, smart; an all-court player with deep, heavy groundstrokes and a silky, unreadable serve. He even had good court manners — that is, he didn't seem like a jerk.

Djoković's game then seemed to mature at an unnatural speed. He beat Nadal in Miami in early 2007, becoming the first teenager to win that tournament since Andre Agassi in 1990. He made the semifinals at the 2007 French, and did the same at Wimbledon, losing to Nadal each time. Then, in August, he stormed through a glittering field in Montreal, defeating, in consecutive matches, the No. 3, No. 2, and No. 1 players in the world — Andy Roddick, Nadal and Federer. Djoković himself was soon the new No. 3. He reached the finals at the U.S. Open, where he held seven set points against Federer, converted none, and lost. Notice had been served, though. There was a new pretender to the throne.

There was also a new court jester. Djoković, whose English is good, had been showing an unusual ease in the spotlight all year. He made Boris Becker blush crimson when, after a tournament in California, he casually told a packed stadium, "You know, when my mother was giving me the milk, I was watching Boris winning the Wimbledon, and now he is giving me the trophy." At the U.S. Open, seconds after a tough quarterfinal win, a dim-witted TV interviewer asked Djoković to do a couple of his imitations, already renowned in tour locker rooms, of his fellow players. He reluctantly obliged, first taking off Nadal — sprinting around the baseline, elaborately adjusting his socks, then trying, even more elaborately, to get his crotch properly organized inside imaginary tight clam-diggers. He then did his Maria Sharapova, and managed to catch every bounce and hair-tuck tic of her pre-service routine, all with his ass stuck out just so. It was pro-level mimicry. The video clips became must-sees on YouTube, and New York fell hard for the big-hitting, bristle-haired kid from Belgrade. Robert De Niro sat in Djoković's player's box for the Open finals. So did Sharapova.

Roger Federer, though, was not amused. Asked at a press conference about Djoković's imitations, he said, "He's walking on a tightrope, for sure." Reporters, meanwhile, pressed Djoković to do his Federer. "I really cannot do Roger," he protested. "He's the untouchable one. He is too perfect." But then a grainy locker-room video surfaced featuring Djoković, egged on by other players, performing a hilarious Andy Roddick and then a show-stopping Federer. He catches Federer's way of holding his upper body on court and tossing his hair between points. But the devastating bit was the groundstrokes follow-through, which was startlingly Federeresque — except exaggerated, parodied, and unsubtly feminized. The other players in the locker room laugh themselves sick as Djoković prances around, fine-tuning the follow-through and then finishing by applauding himself and an imaginary stadium with a self-satisfied smile that's eerily Roger.

I asked Djoković, when we sat down in December, about Federer's tightrope comment. He seemed unfamiliar with it. "I don't see any reason why he should walk on a tightrope."

"No. He thinks you are."

"Oh."

Federer, it should perhaps be noted, is a supremely cool character, both on the court and off. He doesn't seem to have sweat glands. He dissects opponents with a terrible precision, and has been known to wear a cream-colored blazer onto Centre Court at Wimbledon — certainly the only player in the modern era who could carry that off. Nadal, the young bull from Mallorca, is, in his pirate pants and sleeveless muscle shirts, Federer's stylistic opposite. He arrives for matches drenched in sweat, roars or groans with every shot, and overpowers opponents with hustle and superhuman topspin. And now comes Djoković — known also, since New York, as the Djoker. On the sweaty-passion scale, he falls somewhere between the two. He plays with fire and flair, his hedgehog hair standing on end, and the world's tennis fans — most of them, at least — swoon. What few see, however, is the weird and heavy burden he carries everywhere simply because of where he comes from.

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