Fans from across the world have flocked to Shanghai to feel the heart-pounding excitement of the Masters Cup, a showdown pitting the world's most skilled tennis players against one another.

"The (Masters) is special because it gathers the biggest stars in the sport," said Swiss spectator Rolf Wallner, who is attending the Shanghai event with his wife for the second time to cheer for his countryman, world No 1 and defending champion Roger Federer.

Although the trip is a bit on the expensive side - about $600 for the tennis tickets alone, plus traveling and accommodations - the competition between the world's most dominant players was too intriguing for the couple to resist.

"We knew what to expect this year. We came for the second time because we saw during the first time that it was great," he said. "Maybe we will come next year. But we need time and money. The trip is not cheap."

Wallner, who is an airport authority in Switzerland, combined his trip for the Masters Cup with a four-day tour of Beijing last year. To support his idol, Federer, Wallner was dressed in a custom-made T-shirt and wrapped in a national Swiss flag, sporting sunglasses bearing a red cross.

According to organizers, ticket sales for this year's Masters have increased by 30 percent compared to last year, largely due to the rising popularity of the sport and the epic performances of last year.