<p>Defending champion Serena Williams slugged her way to a US Open title rematch against Victoria Azarenka as the top two seeds scored straight-sets knockouts in their semifinals on Friday.<br /><br /></p>.<p>World number one Williams thrashed a rattled Li Na 6-0, 6-3 overcoming some staunch resistance at the end, while Azarenka returned to the Flushing Meadows final with a 6-4, 6-2 win over unseeded Italian Flavia Pennetta.<br /><br />"Just to be able to defend a title for once would be really awesome," said French Open winner Williams, who will get her chance on Sunday after failing to go back-to-back following her 1999, 2002 and 2008 titles in New York.<br /><br />Although overpowered in the opening set, Li battled valiantly in the second, saving six match points to hold serve before the top seed finally closed the deal on a seventh with an unreturned serve.<br /><br />Williams, hot off a 6-0, 6-0 quarterfinal win against Spain's Carla Suarez Navarro, had won 24 consecutive games before Li held serve in the second game of the second set.<br />"To hear constantly, 'go Serena, go Serena,' it is really a pleasure. I hear young voices and older voices and it really makes me feel so special," said Williams. Williams and Azarenka's final will be the first back-to-back title clash at the US Open since Serena and her older sister Venus battled for the crown in 2002.<br /><br />Belarusian Azarenka trails 12-3 head-to-head against Williams, but has won two of their last three matches including the two hardcourt finals in Doha and Cincinnati.<br />"When you play against Serena, you have to play your best," said Azarenka. <br /><br />Williams is bidding for a fifth US Open title and her 17th in Grand Slams.<br />At 31, she would become the oldest women's winner at Flushing Meadows since tennis turned professional in 1968, supplanting Australia's Margaret Court who won in 1973.<br />Australian Open champion Azarenka booked her return to the Championship match by finally finding a way to hold serve in a contest littered with 13 service breaks. In the end, Azarenka's power was too much for the battling Pennetta, who returned from a serious wrist injury to reach her first Grand Slam semi-final.<br /><br />There were five service breaks in a row before Azarenka held to win the first set after her unseeded 31-year-old opponent saved five set points. The second set followed a similar pattern, with three broken serves before Azarenka turned up the power.<br /><br />After holding serve to lead 3-1, Azarenka broke Pennetta yet again and squealed with delight after closing out the 94-minute match with a well-placed forehand.</p>
<p>Defending champion Serena Williams slugged her way to a US Open title rematch against Victoria Azarenka as the top two seeds scored straight-sets knockouts in their semifinals on Friday.<br /><br /></p>.<p>World number one Williams thrashed a rattled Li Na 6-0, 6-3 overcoming some staunch resistance at the end, while Azarenka returned to the Flushing Meadows final with a 6-4, 6-2 win over unseeded Italian Flavia Pennetta.<br /><br />"Just to be able to defend a title for once would be really awesome," said French Open winner Williams, who will get her chance on Sunday after failing to go back-to-back following her 1999, 2002 and 2008 titles in New York.<br /><br />Although overpowered in the opening set, Li battled valiantly in the second, saving six match points to hold serve before the top seed finally closed the deal on a seventh with an unreturned serve.<br /><br />Williams, hot off a 6-0, 6-0 quarterfinal win against Spain's Carla Suarez Navarro, had won 24 consecutive games before Li held serve in the second game of the second set.<br />"To hear constantly, 'go Serena, go Serena,' it is really a pleasure. I hear young voices and older voices and it really makes me feel so special," said Williams. Williams and Azarenka's final will be the first back-to-back title clash at the US Open since Serena and her older sister Venus battled for the crown in 2002.<br /><br />Belarusian Azarenka trails 12-3 head-to-head against Williams, but has won two of their last three matches including the two hardcourt finals in Doha and Cincinnati.<br />"When you play against Serena, you have to play your best," said Azarenka. <br /><br />Williams is bidding for a fifth US Open title and her 17th in Grand Slams.<br />At 31, she would become the oldest women's winner at Flushing Meadows since tennis turned professional in 1968, supplanting Australia's Margaret Court who won in 1973.<br />Australian Open champion Azarenka booked her return to the Championship match by finally finding a way to hold serve in a contest littered with 13 service breaks. In the end, Azarenka's power was too much for the battling Pennetta, who returned from a serious wrist injury to reach her first Grand Slam semi-final.<br /><br />There were five service breaks in a row before Azarenka held to win the first set after her unseeded 31-year-old opponent saved five set points. The second set followed a similar pattern, with three broken serves before Azarenka turned up the power.<br /><br />After holding serve to lead 3-1, Azarenka broke Pennetta yet again and squealed with delight after closing out the 94-minute match with a well-placed forehand.</p>