Australian Open 2014: Defending champion Victoria Azarenka and Maria Sharapova into fourth round

Azarenka broke unseeded Yvonne Meusburger's serve twice in the first four games and was rarely troubled (EPA)

Two-time defending champion Victoria Azarenka made it all look routine Saturday in defeating unseeded Yvonne Meusburger 6-1, 6-0 in a third-round match at the Australian Open.

Azarenka broke Meusburger's serve twice in the first four games and was rarely troubled in exactly one hour to advance to a fourth-round match against American Sloane Stephens.

Last year, Azarenka beat Stephens in the semifinals at Melbourne Park under acrimonious circumstances when Azarenka took a questionable medical time out while trailing Stephens. When Azarenka returned, she broke Stephens' serve and went on to win the match.

"Sloane is a great player, she's improved so much from last year," Azarenka said Saturday.

Earlier, the girlfriend and boyfriend pair of Maria Sharapova and Grigor Dimitrov both advanced along with Wimbledon champion Andy Murray and 17-time Grand Slam winner Roger Federer.

And finally, the oppressive heat wave of the past four days gave way to more benign conditions.

Sharapova, who endured the worst of the torrid heat in her second-round match, beat Alize Cornet 6-1, 7-6 (6) to reach the fourth round. The match was played in high humidity but in temperatures of about 22 Celsius, considerably cooler than the scorching 42 C conditions she endured for 3 hours, 28 minutes in her second-round win on Thursday.

Sharapova will next play Dominika Cibulkova, who beat No. 16 Carla Suarez Navarro 6-1, 6-0 in 59 minutes. Former No. 1-ranked Jelena Jankovic had a 6-4,7-5 win over Kurumi Nara, her third consecutive victory over a Japanese player.

Sharapova, who endured the worst of the torrid heat in her second-round match, beat Alize Cornet 6-1, 7-6 (6) to reach the fourth round (EPA)

Fifth-seeded Agnieszka Radwanska had a 5-7, 6-2, 6-2 over No. 29 Anastasia Pavlyuchenkova and will next play Garbine Muguruza of Spain, who beat former No. 1-ranked Caroline Wozniacki 4-6, 7-5, 6-3.

No. 13 Stephens, who had an upset win over Serena Williams in the quarterfinals here last year, reached the fourth round at a fifth consecutive major with a 7-5, 6-4 win over Elina Svitolina of Ukraine and a date with Azarenka.

Williams will play her fourth-round match Sunday against former French Open champion Ana Ivanovic. Three-time defending champion Novak Djokovic plays Fabio Fognini, also in an afternoon match on Rod Laver Arena.

AP