Novak Djokovic was standing on top of the world yesterday. Well, maybe not exactly on top of the world. Nevertheless the view had to look spectacular to the No. 1-ranked Serbian while posing on the observation deck of the Empire State Building in New York City the day after defeating defending champion Rafael Nadal in the finals of the U.S. Open. Clutching the championship trophy, Djokovic was still glowing after his grueling four-set victory over the Spaniard Monday evening. By winning his first U.S. Open title, Djokovic became the sixth male player in the Open era to win three of the four Grand Slams in the same year. The Belgrade native won the Australian Open in January and Wimbledon in early July. With two months left in the season, Djokovic, 64-2 on the year, can set his sights on the best won-loss record in the modern era. John McEnroe went 84-3 in 1984. Djokovic has now won four majors — he was victorious at Melbourne in 2008 — and just needs to win the French Open to complete the career Grand Slam. McEnroe called Djokovic’s success in 2011 “the greatest year in the history of our sport, there’s no doubt about it.” Perhaps caught up in the euphoria of the win and the media circus that followed in New York yesterday, Djokovic revealed he may have some aspirations other than tennis. Like, say acting. “Yeah. Why not? I might want to do something if I have time soon. And I would like to. I just think show business is something that attracts me,” he said. Djokovic isn’t going to quit his day job anytime soon, however. “There’s a lot more to prove, a lot more tournaments to win,” he said. “As long as I have the desire to win, to go out there on the court and have the feeling that I’ve had so far in my career — that is to win every single match that I play in — as long as I have that, I’ll be competing.” With no rest for the weary, Djokovic has some other business to take care of. His Serbian teammates need him back in Belgrade as the defending Davis Cup champions contest a difficult semifinal tie with Argentina this weekend.