Under Rafael Nadal's Awesome Pecs Beats Heart of Softie

Sept. 13, 2010— -- World tennis champ Rafael Nadal, whose biceps are practically Spanish national treasures, says the music that turns him on is a world away from the Shakira video that features his rippling muscles.

It's the theme song from "The Phantom of the Opera," called "The Music of the Night." Nadal said, "I love the musical. I was there in New York, watching that I think, six times."

Nadal, whose first U.S. Open championship, which he won tonight with a 6-4, 5-7, 6-4, 6-2 victory over Novak Djokovic, made him the youngest man ever to secure a career grand slam, spoke with "Nightline" recently about what drives him to the No. 1 rank.

A player must win all four Grand Slam competitions -- the Australian Open, French Open, Wimbledon and U.S. Open -- over the years for a career Grand Slam and only a handful of other men in history have done it.

When Nadal steps onto the court he is relentlessly focused. With his U.S. Open win today, he now holds nine Grand Slam titles. What is he thinking about?

"Nothing! Try to put the ball inside," Nadal, whose first language is Spanish, told "Nightline" at a U.S. Open Series event just outside Cincinnati. "The important thing is the shots. It's easier to be a great champion with a lot of shots and nothing of head than a lot of head and nothing of shots."

A clear head is key to delivering the kind of powerhouse shots that he'll need to triumph over his chief rival Roger Federer. Nadal and Federer are the only pair of men to have ever finished five consecutive calendar years as the top two ranked players. Nadal has reclaimed the top spot after winning his fifth French Open on June 7.

Yet the 24-year-old Spaniard known as "Rafa" said he views Federer, 27, of Switzerland, less as an enemy and more as a role model. Nadal told Nightline, "I think to have Roger there was always a reference to improve, and a big motivation to be a better player because you always see a better player than you there."

And despite the fact that Nadal is the man to beat at the U.S. Open, he still thinks Federer is a better player.

"I am not still thinking. I am sure," he said.

Gentleman enough to praise his arch rival, Nadal is also macho enough to reveal that beneath those awesome pecs beats the heart of a true softie. Nadal, who has a girlfriend, still lives at home with his mom and says he is "very happy" to be there and is intent on learning to keep his room tidier to please her.