Is it his success or his sportsmanship? His style or his smile? His greatness or his goofiness? When Roger Federer plays tennis the world holds its breath. And there was a collective sigh of rapturous relief Sunday when the Swiss superstar defeated rival Rafael Nadal to win the Australian Open – and an elusive 18th grand slam title. Federer’s stunning victory, after a six-month absence from the sport because of injury, prompted an outpouring of love on social media. READ: Federer savors ‘extra special’ win READ: We’ll party like rock stars His 6.6 million Twitter and 15 million Facebook followers were joined by sporting celebrities – Formula One world champion Nico Rosberg, PGA Championship winner Rory McIlroy, Olympic legend Usain Bolt and Indian cricketer Sachin Tendulkar – in congratulating the 18-time major winner. Just like Bolt, Tendulkar and footballer Cristiano Ronaldo, Federer has transcended his sport. Visit cnn.com/tennis for more news and videos To mark Federer’s remarkable Melbourne feat, CNN Sport has picked 18 reasons to fall in love with the 35-year-old – and all is revealed in the video at the top of this page.