A dominating win by Roger Federer in his 1,000th career match and a more difficult workout for Rafael Nadal set up a rare Grand Slam marquee semifinal between the former top-ranked players.
Four-time Australian Open champion Federer advanced to his ninth straight semifinal at Melbourne Park with a 6-4, 6-3, 6-2 quarterfinal win Tuesday over Juan Martin del Potro, the man who beat him for the U.S. Open title in 2009.
Federer's 1,000th match was similar to most in his career -- no-nonsense, dominating from the start and hitting some incredible shots.
"It's a lot of matches and a lot tennis," said Federer, a record 16-time Grand Slam champion. "Either I have been around for a long time or I'm extremely fit. You decide which way you want to describe it. But I'm happy."
In an often tempestuous night match at Rod Laver Arena, Nadal advanced with a tough 6-7 (5), 7-6 (6), 6-4, 6-3 win over Tomas Berdych.
"Happy with how I finished match physically, I was able to keep running with high intensity," Nadal said.
Federer and Nadal -- they were ranked 1-2 for many years -- have been on opposite halves of the draw since the 2005 French Open. That was the last time the pair met in a Grand Slam semifinal, won that year by Nadal in four sets.
Defending women's champion Kim Clijsters, still dealing with a left ankle injury, advanced to an Australian Open semifinal against third-seeded Victoria Azarenka by beating No. 1 Caroline Wozniacki 6-3, 7-6 (4), Tuesday. Clijsters' victory ensured that Wozniacki would lose the top ranking she has held for most of the last 15 months.
Azarenka beat No. 8 Agnieszka Radwanska, 6-7 (0), 6-0, 6-2. Azarenka is one of three women who could finish at No. 1 -- Maria Sharapova and Petra Kvitova are the others.
Sharapova remains perfect in Australian Open quarterfinals, defeating Ekaterina Makarova, 6-2, 6-3, today.
Sharapova has won all five quarterfinals she has contested at Melbourne Park and has advanced to the final twice, including when she won the title in 2008. The 24-year-old Russian, who has lost just 21 games in five matches, will play Wimbledon champion Kvitova in the semifinals. No. 2 Kvitova beat Sara Errani of Italy, 6-4, 6-4, in the quarterfinals.
The quarterfinals on the other side of the men's draw are today -- Andy Murray plays Kei Nishikori of Japan and top-seeded Novak Djokovic takes on David Ferrer.
Clijsters has needed treatment on her ankle since Sunday, when she injured it and had to save four match points in her fourth-round win over French Open champion Li Na.
"Instead of really focusing on the match, you're focusing on trying to get the ankle as good as possible," Clijsters said of her preparation.