Easy win for Serena

Serena Williams continued her march towards her sixth Australian Open crown with a demolition of Greta Arna in their third round clash at Rod Laver Arena on Saturday night.

The 12th seed needed just 59 minutes to wrap up the 6-1 6-1 victory and join glamour girls Maria Sharapova and Ana Ivanovic in the fourth round with seventh seed Vera Zvonareva the biggest name to fall on day six at Melbourne park.

And while French No.9 seed Marion Bartoli also bowed out, there were no such worries for second-seeded Czech Petra Kvitova, who advanced after being handed an early finish thanks to an injury to Maria Kirilenko.

German 14th seed Sabine Lisicki is through to the fourth round at Melbourne Park for the first time, while unseeded Italian Sara Errani is also through to the last 16.

Williams was in a ruthless mood from the outset, racing out to a 5-0 lead with Hungarian world No.92 no match for the American's power hitting.

Arn did manage to avoid the bagel set, but Williams strung together another five straight games to take the set and a 4-0 lead in the second.

Arn briefly halted the momentum to claim her second game, but it mattered little as she double-faulted to hand Williams the easiest of passages into the final 16 where she will meet unseeded Ekaterina Makarova grabbed another upset, this time at the expense of fellow Russian Vera Zvonareva, the No.7 seed.

Two days after sending Estonian 25th seed Kaia Kanepi packing, Makarova made it back-to-back boilovers when she overcame an early 3-0 deficit against Zvonareva and then also the disappointment of failing to serve out the set at 6-5.

She would eventually take the opening set in the tie-breaker and from there it was all Makarova as she broke twice more in the second before eventually serving it out to complete a 7-6 (9-7) 6-1 victory.

Having conceded only two games in total in her first two matches, 2008 champion Sharapova continued on her miserly way at Melbourne Park against German 30th seed Angelique Kerber, winning 6-1 6-2.

But the score didn't fully reflect the fight that Kerber showed, particularly in the second set, before she was eventually blown away by Sharapova's power hitting, 34 winners to just 14 a true reflection of the gulf in class between the pair.

The 87-minute win sets up a fourth-round meeting with Lisicki, who was down by a set and a break against Sharapova's 18th-seeded compatriot Svetlana Kuznetsova but rallied to win 2-6 6-4 6-2.

Earlier, Wimbledon champion Kvitova was leading 6-0 1-0 with a break in the second set - having already struck 20 winners - and had been on court only 38 minutes when a groin injury forced Russian 27th seed Kirilenko to retire.

Kirilenko injured herself in the first game and then made it worse attempting a serve volley in the fifth game. But while she took two breaks to receive treatment, it was in vain as she conceded defeat.

Next up for Kvitova, who reached the quarter-finals at Melbourne Park 12 months ago, will be 2008 finalist Ivanovic, who had to fight back in the second set in order to see off American Vania King 6-3 6-4.

Ivanovic has endured a lean run since winning the French Open in 2008, and this is just the fifth time from her past 15 Grand Slams that