Serbian Tennis phenom Novak Djokovic used to be more famous for clowning around than for winning tournaments. On YouTube, you'll find Djokovic (pronounced Joke-oh-vich) performing a karaoke "I Will Survive." He once modeled undies at a fashion show. His impressions of Rafael Nadal, John McEnroe and Maria Sharapova are crowd favorites. "I like to laugh my ass out," Djokovic says. (When you juggle four languages, as he does, you're allowed to jumble a phrase or two.)
But he's not just the Djoker anymore. At a routine hitting session in Los Angeles one August afternoon, he's firing shots that have his sparring partner, an American junior named Marcos Giron, pinballing between the sidelines. At one point, Djokovic, 24, stretches his 6-ft. 2-in. (187 cm) frame like a condor's wings to reach an impossible ball and flicks it just over the net. All Giron can do is put up his hands and mutter to himself. "I didn't take it easy on the junior, poor guy," Djokovic says later.
"Poor guy" describes anyone who faces Djokovic this season. Thanks in part to what his coach, Marian Vajda, calls a "more professional" approach to his game--on stern display this particular afternoon--Djokovic enters the U.S. Open, which starts Aug. 29, on a tear. He has already won the Australian Open and Wimbledon this year. In July, he wrestled the world's top ranking away from Nadal. He owns an incredible 57-2 record for the year, his only losses coming to Roger Federer in the French Open semifinals and to Andy Murray on Aug. 21 in the final of the Western and Southern Open. (A sore shoulder forced Djokovic to retire in the second set.)
In 1984, McEnroe set the standard for tennis dominance with an 82-3 season, a .965 winning percentage. Djokovic could top that. He's not only turning in the finest tennis season in a generation: so far, his 2011 is among the most dominant performances in sports history. He's also giving tennis fans a chance to expand their palette. For the past half-dozen years, the styles of Roger Federer, a graceful legend who treats the court like his canvas, and Nadal, the bemuscled raging bull, have defined the aesthetics of men's tennis. The aficionado had to pick sides: tennis as art or street fight? Now here comes Djokovic, a hybrid of the two. "He has a fire in his eyes like Nadal," says Janko Tipsarevic, the 20th-ranked player in the world and a fellow Serb. "And he might not be as smooth as Roger, but he's close."
How did Djokovic crash the Roger-Rafa chess match? The key is his physical conditioning. For years, he had a reputation for fading in long matches. Players such as Federer and Andy Roddick publicly questioned his toughness. "I started feeling really weak if I go the distance," Djokovic admits. "It got to me in the end." This off-season, however, a nutritionist discovered that Djokovic was sensitive to gluten, a protein found in most breads, cereals and pastas. Fatigue is a symptom of gluten sensitivity, so he stopped eating it. "I feel much better now and have not had much trouble with the breathing, thank God," he says.
He has also started a fad. Back in his native Serbia, where Djokovic has outsize celebrity influence, swearing off gluten is now all the rage. "People think that will solve all their problems as well," says Vladimir Petrovic, Serbia's ambassador to the U.S.