Federer,Nadal on course for semis showdown after easy wins

Big guns move into round four with straight sets wins,Wozniacki through too

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 semifinal matchup at the Australian Open. On the womens side,a rematch of the 2011 final is already in place,with defending champion Kim Clijsters and Chinas Li Na both winning later Friday to set up a meeting in the fourth round.

Neither the four-time Australian champion Federer nor 2009 title-holder Nadal have dropped a set so far,although Federers path has been made easier by a walkover in the second round. The longtime rivals played back-to-back matches at Rod Laver Arena on Friday. Nadal,his right knee still taped from a recent injury,showed no problems while moving briskly around the court in a 6-2,6-4,6-2 win over qualifier Lukas Lacko.

Federer followed in the marquee matinee program by beating Ivo Karlovic 7-6 6,7-5,6-3,saving a set point in the first set tiebreaker with a scrambling lob over the 6-foot-10 Croatian. Federer will play Australian teenager Bernard Tomic on Sunday in the fourth round. Nadal will meet fellow Spaniard Feliciano Lopez,who beat No. 16 John Isner 6-3,6-7 3,6-4,6-7 0,6-1 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. Other winners of the day include Tomas Berdych,who defeated Kevin Anderson and Nicolas Almagro,who got the better of Stanislas Wawrinka in straight sets.

While Germanys Philipp Kohlschreiber and Juan Martin Del Potro also won without dropping a set, local lad Bernad Tomic defeated 13th-seeded Alexandr Dolgopolov of Ukraine 4-6,7-6 0,7-6 6,2-6,6-3.

Wozniacki,Clijsters through

On the womens side,top-seeded Caroline Wozniacki also has not dropped a set in advancing to the fourth round as she continues her quest for a first Grand Slam title. She beat Monica Niculescu of Romania 6-2,6-2,while third-seeded Victoria Azarenka defeated Mona Barthel 6-2,6-4. In the tougher half of the womens draw,Wozniacki could face Clijsters in the quarterfinals,but before Clijsters gets that far,she will have to beat French Open winner Li. Li advanced to the fourth round when her opponent,Anabel Medina Garrigues of Spain,had to retire in the first set after badly twisting her right ankle in the first set. Clijsters advanced with a 6-3,6-2 win over Daniela Hantuchova earlier at Hisense Arena,who admitted to not playing her best tennis. The other half of the draw will see five-time champion Serena Williams and 2011 Wimbledon winner Petra Kvitova,play for a spot in the last 16 on Saturday.

Wozniacki,who needs to reach the quarters to have any chance of retaining the No. 1 ranking,wasted one match point and was broken when she was serving for the match. But she broke back immediately to move into a final 16 encounter against Jelena Jankovic. Azarenka,who is in with a shot of reaching the top of the rankings,will next meet Czech player Iveta Benesova.