By Greg Stutchbury
MELBOURNE (Reuters) - Top seed Serena Williams and her older sister Venus sent a chilling warning to the rest of the women's draw at the Australian Open on Saturday by both advancing to the fourth round at Melbourne Park for the first time in five years.
Both took a little while to figure out their opponents on Saturday but once they got into the groove of the match were able to advance relatively comfortably.
World number one Serena beat Ukraine's Elina Svitolina 4-6 6-2 6-0, while 18th seed Venus also needed a set to get going before she beat Italy's Camila Giorgi 4-6 7-6(3) 6-1.
Men's champion Stan Wawrinka avoided a repeat of the stunning upset of compatriot Roger Federer on Friday, with a 6-4 6-2 6-4 win over Finland's Jarkko Nieminen, while eighth seed Milos Raonic cruised past Germany's Benjamin Becker 6-4 6-3 6-3.
"I'm really happy with my game so far, I was aggressive, took control of the match and I think my game is there," Wawrinka said in a courtside interview. "I'm happy to get through again.
"I've been here 10 days before the tournament and this is a new challenge for the next two weeks and that is what I'm focussed on."
Women's sixth seed Agnieszka Radwanska also continued her largely untroubled, yet under the radar, progress through the draw with a 6-0 7-5 win over Varvara Lepchenko and will meet Venus on Monday.
"I think playing her is always great challenge," Radwanska said. "I think she is still playing great tennis even she's a bit older. She's still really fit and playing a high level.
"I think it's going to be another good match."
The last time the Williams sisters reached the last 16 at Melbourne Park, Serena went on to win her fifth title. It was also the last time the 18-times grand slam winner lifted the Daphne Akhurst Memorial Cup.
Chances of her adding a sixth looked bleak early on in her clash with the 20-year-old Svitolina, who showed why she is considered one of the more promising players in women's tennis when she got off to a flying start at the Rod Laver Arena.
The American took the loss of her first set at Melbourne Park this year to heart and roared through the rest of the match in just over an hour to end Svitolina's hopes of becoming the first Ukrainian woman to reach the fourth round at the Australian Open since Alona Bondarenko in 2010.
"She played really well," Serena said of Svitolina. "She is one to watch. She has come a really long way. It was a good match and she really made me work really hard."
Serena will now play the enigmatic Garbine Muguruza in the next round after the Spaniard beat Switzerland's Timea Bacsinszky in three sets.
The hard-hitting Muguruza beat Serena last year in the second round at Roland Garros and the tall right hander said that victory, while a 'perfect game', was not a factor on the Melbourne hard courts.
"I think I don't have nothing to lose," the 21-year-old said. "Just another match, same game, same concentration. Nothing new. ... I don't think I have pressure."
While Serena was recovering on Rod Laver Arena, older sister Venus was wrapping up her win over the tricky Giorgi to move into a grand slam fourth round for the first time since Wimbledon in 2011.
"That feels fantastic especially when things happen in your life that are not in your control," said the 34-year old, who struggles with Sjogren's syndrome, an auto-immune disease that can cause joint pain and fatigue.
"But I don't want to stop now, I want to keep it going.
"This little cat has a few tricks up her sleeve."
(Editing by Sudipto Ganguly)