MELBOURNE, Australia (AFP) — Serena and Venus Williams answered the challenge of Belgian pair Kim Clijsters and Justine Henin in emphatic fashion yesterday as they both crushed second-round opponents at the Australian Open.

Serena demolished Petra Kvitova of the Czech Republic, 6-2, 6-1, on the Hisense Arena, immediately after Venus had disposed of crafty Austrian Sybille Bammer, 6-2, 7-5, on the same court.

However, former world number one, Ana Ivanovic, showed just how far she has fallen as she was bundled out by unseeded Argentine Gisele Dulko, 6-7 (6/8), 7-5, 6-4.

On a good day for the seeded players, fourth-ranked Dane Caroline Wozniacki crushed German Julia Goerges, 6-3, 6-1, Belarusian Victoria Azarenka (seeded seven) beat Swiss teenager Stefanie Voegele, 6-4, 6-0, and Russia’s Vera Zvonareva (nine) smashed Czech Iveta Benesova, 6-0, 6-3.

But it was Serena who impressed most as she wiped out the challenge of 19-year-old Kvitova in only 67 minutes.

Kvitova matched it with Williams for five games in the first set before the world number one stepped up a gear and blitzed her way through the rest of the match.

Williams, a four-time champion here, warned she would only get better from here.

Meanwhile, Venus said she was now playing a style of attacking tennis that naturally suits her after she powered past Bammer.

The seven-time Grand Slam winner has never won the Australian Open and she would likely have to get past Wozniacki in the quarters and Serena in the semis to have a shot in 2010.

If anyone can stop the Williams juggernaut it could well be 2009 US Open runner up Wozniacki.

She was highly impressive in her win over Goerges, breaking the German once in the first set and twice in the second.

Thirteenth seed Samantha Stosur kept Australian hopes alive as she beat German Kristina Barrois, 7-5. 6-3, while China’s Li Na joined countrywoman Zheng Jie in the third round when she beat Hungary’s Agnes Szavay, 3-6, 7-5, 6-2.