Serena Williams moved a step closer to successfully defending her Australian Open title and extracted some family revenge on Saturday with a 6-0, 6-3 victory over Carla Suarez Navarro. Last year, Suarez Navarro beat Venus Williams in the second round and made it to the quarterfinals. The Spaniard didn't even get close this time, and the Williams sisters remained on course for a semifinal meeting when Venus held off Australia's Casey Dellacqua 6-1, 7-6 (4), closing with an ace on her fourth match point.Serena Williams' only real difficulty was in closing the first set, needing eight set points in a game that went to deuce 13 times and lasted longer than the previous five games combined. "It was definitely the toughest 6-Love set," she said. "I thought, 'OK, Serena, don't put too much pressure on this. Worst case scenario it will be 5-1. But way to keep fighting."No. 1-ranked Roger Federer had no trouble in a 6-3, 6-4, 6-4 win over No. 31 Albert Montanes of Spain. It was the 28-year-old Swiss star's 50th win at Melbourne, where he has collected three of his record 15 Grand Slam singles titles. "It was important to come through the first week," Federer said. "I feel good, I feel confident. Physically I'm fine and mentally fresh and that's the way you want to go into the second week."Nikolay Davydenko, Federer's potential quarterfinal opponent, extended his impressive winning run with a 6-0, 6-3, 6-4 victory over No. 30 Juan Monaco of Argentina. Davydenko will next face Fernando Verdasco, who lost an epic, five-set semifinal to eventual champion and fellow Spaniard Rafael Nadal last year. The sixth-seeded Davydenko counts wins against Federer and Nadal at last year's World Tour Final and this season's opening event at Doha among his 12-match winning streak.