Rafael Nadal, Roger Federer advance

KEY BISCAYNE, Fla. -- Rafael Nadal and Roger Federer have played each other 22 times on hard courts, grass and clay. Now, for the first time in six years, the best rivalry in tennis is back on U.S. soil.

Rafa and Roger will meet Friday night in the semifinals at the Sony Ericsson Open. Their most recent matchup in North America took place on the same court in 2005, when Federer beat Nadal for the Key Biscayne title.

"We really get up for these kind of matches against each other because we know the world is watching," Federer said. "We always have these incredible points and incredible matches."

The top-ranked Nadal advanced to the semifinal showdown by beating No. 7-seeded Tomas Berdych 6-2, 3-6, 6-3 on Thursday night. Federer won earlier without breaking a sweat when Gilles Simon retired with a stiff neck after losing the first three games.

Nadal vs. Federer has played out in eight countries and one principality on four continents, producing some of the sport's most dramatic moments. Federer owns a record 16 Grand Slam titles but is only 8-14 against Nadal, including 2-6 in major tournaments. They've tussled on even terms in recent years for the No. 1 ranking.

"We have that history, and nobody can take it away from us," Federer said. "We've played in so many big finals against each other and were able to play over four or five tough sets and have always shown a lot of respect toward each other. If you win, great; if you lose, that's OK, too, as long as you tried everything and learned something. But I am planning to win."

Their first meeting was at Key Biscayne in 2004, when a 17-year-old Nadal upset Federer in the third round. Federer was then in the midst of a record five-year reign at No. 1, but he lost six of the first seven times he played Nadal -- and found it most annoying.

"Early on in my career, when I became the world No. 1, I didn't really have that rival, and I was very happy about it," Federer said. "I was just able to win, win, win and dominate. That was quite incredible.

"So in the beginning, I guess I struggled to embrace the rivalry I had with Rafa. Only later on I was able to say, 'This is actually quite cool.' He was sleeveless with pirate pants, long hair, a lefty. ... It all kind of made sense, and I was able to embrace it then," he said.

Federer won the most recent matchup for the title in the ATP World Tour Finals in London last November. Nadal won their only other meeting last year in the Madrid final.

"It's special always to play against him," Nadal said. "We always had the big respect for each other. We are closer than before, like friends, because we spend a lot of time together with exhibitions, with the council of the ATP. We have a fantastic relationship."

While most of their showdowns have been in finals between Nos. 1 and 2, they'll play this time in the semis because Federer recently slipped to third in the rankings behind Novak Djokovic. The other match Friday pits the Serb against American Mardy Fish.

Nadal took an early lead against Berdych before requiring treatment from a trainer. Nadal said he injured a nerve in his right arm, and pain ran up his shoulder to his neck and made him dizzy.

"Really strange," he said. "I was thinking too much about the arm, and I lost a little bit the concentration."

The Spaniard was on the verge of falling behind when serving at 0-40 in the opening game of the final set. He hit three consecutive aces and held, broke in the next-to-last game and served out the match at love.

A jubilant Nadal threw his sweaty wristband into the stands right-handed -- an indication his shoulder wasn't too sore.

By comparison, Federer easily advanced. He won 12 of the 15 points and was done in 10 minutes when Simon offered a handshake in concession.

"It's not the way you want to move on," Federer said. "But, look, I'll take those, because they happen quite rarely."

Simon headed for the exit as fans booed, and the Frenchman understood their disappointment.

"The public pays the ticket to see the players," Simon said. "It's tough for them to see Roger only 10 minutes. But of course the sadness on the court is me for sure. You have to play 100 percent if you want to have a chance to win. When you play Roger, you have to play more than that."

Simon said he aggravated a recurring problem with his neck warming up before the match.

"I didn't know anything coming in," Federer said. "You get booed off the court -- that's rough. But that's how it goes."