Second seed Czech Petra Kvitova battled her way into the Australian Open third round on Thursday as rivals Serena Williams and Maria Sharapova steamrolled their respective opponents. Russia's Vera Zvonareva and Serbian glamour girl Ana Ivanovic also won in straight sets as the cream continued to rise to the top of the women's draw. However Wimbledon champion Kvitova had to survive a second-set meltdown against Carla Suarez Navarro, who bundled Venus Williams from the tournament in 2009. Kvitova won the first set easily but grew visibly frustrated as she lost the second and had to come from a break down in the third to win 6-2, 2-6, 6-4. The reigning Wimbledon champion was in great touch in the first set, serving well and breaking the Spaniard twice in a commanding display. But at the start of the second Kvitova seemed to lose focus, missing easy shots and allowing Suarez Navarro to dictate the points. The Spaniard, one of only seven players in the top 100 with a one-handed backhand, used it to devastating effect to move Kvitova around the court. Suarez Navarro took the second and broke to go 2-0 ahead in the decider, but Kvitova dug deep and slowly pegged back the gallant Spaniard, eventually winning a tense encounter in 1hr 47mins. Earlier, five-time champion Williams brushed off fears about her injured ankle as she beat Czech Barbora Zahlavova Strycova 6-0, 6-4 to record her 500th career win. The American 12th seed, who pulled out of this month's Brisbane International after rolling her ankle on court, fell awkwardly in the final game of the match. "It's fine, I just have really wobbly ankles," she said. "I wasn't meant to be a ballerina." Sharapova lost just one game as she dismantled US qualifier Jamie Hampton 6-0, 6-1. Sharapova, 24, dominated Hampton in all areas, hitting 23 winners to six and making 77 percent of her first serves to her opponent's 50 percent. "I didn't know much about my opponent so it was more a matter of getting my feet going and worrying more about myself and trying to improve from the first round," Sharapova said. The Russian next faces Germany's Angelique Kerber, a 7-5, 6-1 winner over Canadian Stephanie Dubois. Zvonareva, who this time last year was ranked number two in the world, was almost as impressive as Sharapova as she downed Czech Lucie Hradecka. After racing through the first set, Zvonareva held off a spirited fight-back from Hradecka to win 6-1, 7-6 (7/3) and set up a third round clash with another Russian, Ekaterina Makarova. Makarova upset Brisbane International winner and the tournament's 25th seed, Kaia Kanepi of Estonia, 6-2, 7-5. Ivanovic, whom Sharapova defeated in the 2008 final, reached the third round at Melbourne Park for the fifth time when she downed Michaella Krajicek of the Netherlands 6-2, 6-3. The former world number one lost in the first round last year but said she was in much better form 12 months down the track. "I worked a lot on my game in the off-season," she said. "When I'm out there I really know what I have to do and I stay with it." American Vania King upset 15th seeded Russian Anastasia Pavlyuchenkova 5-7, 6-3, 6-4, while Italy's Sara Errani beat another Russian seed, the 29th ranked Nadia Petrova 6-2, 6-2. China's Zheng Jie, who made the semi-finals in 2010, upset 23rd seed Roberta Vinci of Italy 6-4, 6-2, while 14th seed Sabine Lisicki of Germany thumped Israel's Shahar Peer 6-1, 6-2.