Serena Williams rebounded from her shaky start to the year with an awesome demonstration of her Australian Open intent at the Sydney International on Tuesday. The world number two showed no signs of rustiness in her scrappy first-round win over Samantha Stosur as she demolished Italy's Sara Errani 6-1, 6-2. The American belted nine aces past her bewildered opponent in an ominous warning to her rivals ahead of next week's first Grand Slam of the season. The powerful Russian contingent also flexed their muscles, with Dinara Safina, Elena Dementieva and Svetlana Kuznetsova all advancing to Wednesday's quarterfinals. World number three Safina was ruthless in her 6-3, 6-0 win over fellow Russian Vera Dushevina while Kuznetsova showed her determination to get out of a tight corner in her 6-2, 2-6, 7-6 victory over Estonia's Kaia Kanepi. Dementieva chalked up her seventh straight win this year in defeating Slovakia's Jarmila Gajdosova 6-2, 6-4. With the top four seeds, headed by reigning Australian Open champion Novak Djokovic, all given byes into the second round, Tuesday's men's matches contained plenty of surprises. Last year's champion, Russian Dmitry Tursunov was bundled out by Richard Gasquet of France 7-6, 6-4, while last week's Brisbane International winner, Czech Radek Stepanek retired in the second set against France's Jeremy Chardy while trailing 6-4, 3-0. Sixth seed Tomas Berdych of the Czech Republic struggled to contain the booming serve of Australian Chris Guccione, a finalist in Sydney last year, as he suffered a 6-3, 6-4 defeat. Eighth-seeded American Mardy Fish fell to Serbia's Janko Tipsarevic while Lleyton Hewitt, a four-time title winner in Sydney, defeated Julien Benneteau of France 5-7, 6-2, 6-4. Australian Hewitt started his comeback last week after hip surgery and said he was slowly growing in confidence. Hobart loses all seeds Italian top seed Flavia Pennetta's defeat completed a wipe-out of all eight seeds at the Hobart WTA International on Tuesday. Pennetta crashed out to world number 58 Magdalena Rybarikova of the Slovakia, 7-5, 6-3 to leave no seeds left as the tournament enters the quarterfinal stage on Wednesday. Two other seeds, number four Zheng Jie of China and Ukraine's seventh seed Alona Bondarenko, bowed out on Tuesday. Argentina's Gisela Dulko eliminated Zheng 6-3, 6-3 and Czech world number 48 Petra Kvitova knocked out Bondarenko, 6-2, 6-1. The other ousted seeds were Switzerland's Patty Schnyder, Russian Anna Chakvetadze, Hungarian Agnes Szavay, Canadian Aleksandra Wozniak and Thailand's Tamarine Tanasugarn. Polish qualifier Urszula Radwanska's winning run in the tournament ended when she was forced to retire with a back injury while trailing Hungary's Melinda Czink 2-4 in the opening set. Kohlschreiber hot In Auckland, defending champion Philipp Kohlschreiber overcame a shoulder injury to thrash in-form Dominik Hrbaty in a first-round singles match at the Heineken Open Tuesday. Playing after receiving painkilling injections, the German's serve and ground strokes proved too much for Hrbaty and he wrapped up the match 6-1, 6-2 in just 52 minutes. Latvian star Ernests Gulbis set himself up for a second-round clash with tournament top seed Juan Martin Del Potro after a three-set victory over Spain's Marcel Granollers 6-4, 6-7 (5-7) 6-1. Qualifier John Isner of the US beat seventh seed Albert Montanes of Spain 7-6, 7
