Top seed Caroline Wozniacki and third-ranked Victoria Azarenka both reached the Australian Open's fourth round without dropping a set Friday as they target maiden grand slam wins.
But while Wozniacki cruised past Romania's Monica Niculescu 6-2, 6-2, Azarenka was handed her first real test of the tournament before beating Germany's Mona Barthel 6-2, 6-4.
Wozniacki had been severely tested during her second-round match against Georgia's Anna Tatishvili, but against Niculescu the 21-year-old Dane took control from the outset and never relented.
She won the first set in 31 minutes and only slipped up in the second when, serving for the match at 5-1, she was broken by the Romanian.
But Wozniacki broke straight back to win an entertaining match and move into the fourth round as she bids to retain the top ranking, which could be usurped by Azarenka, Petra Kvitova or Maria Sharapova after the Open.
"There's not too much rhythm playing against Monica," Wozniacki said.
"She slices the ball from both sides, she can play high and she can play aggressive.
"You need to be fast on your feet to win the points because she's so fast."
Azarenka had earlier put aside some contentious line calls in her win over Barthel.
The Belarusian, who had been expected to win easily, showed her anxiety towards the end of the contest when two line calls went against her on her third and fourth match points.
Azarenka had no Hawk-Eye challenges left after three earlier unsuccessful appeals and had to accept the calls, but after winning the match she turned and glared angrily at the official before walking to the net.
She later conceded that she may have overreacted.
"I was wrong three times so it was my fault too," she said, referring to her earlier Hawk-Eye challenges.
Although winning in straight sets, Azarenka never had it her own way against the feisty German, who won her maiden WTA title as a qualifer in Hobart last week after beating the top two seeds along the way.
"Even though I won the first set 6-2 there were a lot of long points, but I was strong and took my chances," she said.
"In the second set I lost my concentration a little but I hung in there."
She now takes on Czech Iveta Benesova, a 6-1, 6-3 winner over Russian qualifier Nina Bratchikova.
Eighth-seeded Pole Agnieszka Radwanska moved through to the fourth round largely unnoticed when she beat Galina Voskoboeva of Kazakhstan 6-2, 6-2.
Radwanska will play Germany's Julie Goerges after the German battled past Italian Romina Oprandi 3-6, 6-3, 6-1.
AFPTags: australian-open, tennis, sport, melbourne-3000, vic, australia First posted January 20, 2012 13:00:09