World number one Serena Williams, her sister Venus Williams and Agnieszka Radwanksa of Poland have progressed to the Singles third round of the Australian Open Tennis tournament, the first Grand Slam of the season. In the second round this morning, while Serena defeated Russia's Vera Zvonareva, 7-5, 6-0, Venus beat fellow American Lauren Davis, 6-2, 6-3. Radwanska eased past Johanna Larsson of Sweden, 6-0, 6-1.Mahesh Bhupathi and his Austrian teammate Jurgen Melzer are now playing their Men's Doubles first round match. Rohan Bopanna, with his Canadian partner Daniel Nestor will play their opening match later in the day.