World number one Novak Djokovic led fellow Serb Janko Tipsarevic into the second week of the Australian Open with a 6-4, 6-3, 7-5 defeat of Radek Stepanek and then blasted disgraced cyclist Lance Armstrong.

Tipsarevic, the eighth seed, came through his second consecutive five-set test, defeating Frenchman Julien Benneteau 3-6, 6-4, 2-6, 6-4, 6-3 for a place in the last 16.

Djokovic then exploded when asked about Armstrong, who on Thursday confessed to doping in every one of his seven Tour de France wins.

“He cheated the sport, he cheated many people around the world with his career, with his life story ... I think he should suffer for his lies all these years,” Djokovic said.

The holder said that he had not been blood tested for half a year, but was still giving urine samples when anti=doping teams came calling.

“Anti-doping regulations a little bit maybe more strict (in tennis) in the sense that you have to fill the whereabouts documents and you have to basically give an hour or two in every day of your life in a whole year, where you are.

“On the other hand, it gives them an opportunity to test you. And you know it is the same for the other players. At least from that point of view, it’s fair.

“I have nothing against the anti-doping federation, association, testing me 10, 20, 30 times a year.”

Spanish 10th seed Nicolas Almagro defeated Jerzy Janowicz 7-6 (7-3), 7-6 (7-4), 6-1 as the Pole copped a fine for a temper outburst this week, in which he hit the umpire’s chair with his racquet over a line call.

In Friday’s last third round match, fourth-seeded David Ferrer of Spain beat Marcos Baghdatis of Cyprus 6-4, 6-2, 6-3, clinching the 1-hour, 57-minute match with an ace.

Elsewhere, fifth-seeded Tomas Berdych beat Jurgen Melzer 6-3, 6-2, 6-2 and will next play South Africa’s Kevin Anderson, who eliminated No. 22 Fernando Verdasco 4-6, 6-3, 4-6, 7-6 (4), 6-2.

Others advancing included Japan’s Kei Nishikori, who will face Ferrer in the fourth round, and No. 8 Janko Tipsarevic, who has a tough next round against No. 10 Nicolas Almagro.

Sharapova, Radwanska on roll

In women’s play, 2008 champion Maria Sharapova overcame a few late niggles to put out Venus Williams 6-1, 6-3. Sharapova was motoring a set and 5-1 when she went off the boil. Williams hung in for 5-3 but was felled by an ace on match point.

“She’s won more Grand Slams than I have (seven to four),” said Sharapova. “I really wanted this victory. I made a few more errors at 5-1 than I wanted, I was happy to serve it out.”

Agnieszka Radwanska ran her undefeated record this season to a dozen matches as she advanced into the fourth round of the Australian Open over Briton Heather Watson 6-3, 6-1.

She moved into a contest with Ana Ivanovic after the 13th seed won the battle of Serbia over compatriot Jelena Jankovic 7-5, 6-3.

Li Na, Kerber through

In other women’s matches, Angelique Kerber survived some nervous moments before fending off American teenager Madison Keys 6-2, 7-5 in their third round match, then got to blow out the candles on a cake to celebrate her 25th birthday.

Local organisers brought a cake onto the court for Kerber immediately after the match and the crowd at Rod Laver Arena sang “Happy Birthday.” She blew out the candles and said thank you to the crowd and to Keys.

Kerber will next play No. 19 Ekaterina Makarova of Russia, who advanced after a tough 6-7 (4), 6-3, 6-4 win over 2007 Wimbledon finalist Marion Bartoli.

Sixth-seeded Li Na advanced with a 6-4, 6-1 win over No. 27 Sorana Cirstea of Romania and will next play No. 18 Julia Goerges, who prevented an all-China fourth round encounter by beating Zheng Jie 6-3, 1-6, 7-5.

More In: Tennis | Sport