MELBOURNE // In the same half of a grand slam singles draw for the first time since 2005, Rafael Nadal and Roger Federer are taking similar paths to a potential semi-final match at the Australian Open.
Neither the four-time Australian champion Federer nor 2009 title-holder Nadal have dropped a set so far, although Federer's path has been made easier by a walkover win in the second round.
The long-time rivals played back-to-back matches at the Rod Laver Arena on Friday.
Nadal, his right knee still taped from an injury, showed no problems while moving briskly around the court in a 6-2, 6-4, 6-2 win over the qualifier Lukas Lacko.
Federer followed in the marquee matinee programme by beating Ivo Karlovic 7-6, 7-5, 6-3, saving a set point in the tiebreaker with a scrambling lob over the tall (2.08m) Croatian.
Federer will play the Australian teenager Bernard Tomic on Sunday in the fourth round.
"He gave me a second serve and gave me a slight chance," Federer said. "Might have had a little bit of a lucky volley …"
Karlovic agreed. "It was unlucky … one in a hundred that I'm going to lose that point," he said.
"I didn't really expect him to do that. I was there, I just miscalculated how much I was jumping. If I would have won that, everything would be different, but that's life."
Nadal had few dramas in his match against Lacko, the Slovak, which is just the way he wanted it. He felt a sharp pain in his knee while sitting in his chair in his hotel on the weekend, an innocent enough movement he initially feared would cause him to withdraw from the tournament.
Three matches later, Nadal said: "The knee is fine … being in the fourth round without losing a set, it's fantastic news."
Nadal will next meet fellow Spaniard Feliciano Lopez, who beat No 16 John Isner 6-3, 6-7, 6-4, 6-7, 6-1 to put the last US man out of the draw.
It is the first time since the start of the Open Era in 1968 that no American men have reached the fourth round at the Australian Open, although no Americans entered the tournament in 1972 and 1973.
The last American to win the Australian Open was Andre Agassi in 2003, his third win in four years at Melbourne Park.
"It's very ugly, to be honest, to have no one in the round of 16 … very disappointing, not a good effort from the Americans," Isner said.
"We've got to try to rectify that next time the big tournaments roll around."