Serena Williams hit eleven aces to down two straight sets, eliminating top seed Caroline Wozniacki 6-2, 6-4 on Saturday night and setting up US Open final clash against Samantha Stosur. Williams, out of tennis for almost a year with a series of injuries, reached her fifth US Open final. The 28th-seeded Williams, who is aiming for her 14th major title and fourth US Open title, has reached the final without dropping a set. Ninth seeded Aussie Stosur advanced to her first US Open final with remarkably little notice, considering she has already played the longest tiebreaker in women\'s major tournament history and won the longest women\'s match time-wise in US Open history during this same tournament. Stosur, 27, beat 92nd-ranked Angelique Kerber of Germany, 6-3, 2-6, 6-2, in an early semi. When Williams, 29, was leading 6-2, 1-0, she had whammed and bammed her way to 20 outright winners to none by the 21-year-old Wozniacki, whose signature style is to run down every shot and send it back. By the end, Williams had 34 winners to only five for Wozniacki, for which made up for the American\'s 34 unforced errors to 12 from the Dane. \"I want to play on 911, so I am eager to reach the final,\" said Williams. There was a worrisome moment for Williams in the first set. During the changeover after Williams had taken a 4-1 lead with a booming forehand volley, she called for the trainer to tend to her big toe. \"I feel there have been some obstacles to get through this tournament,\" Stosur said, \"and to come through the way I have, I\'m really proud of myself for that. To be in the final, getting through those tough matches, I guess that\'s a good thing.\" Stosur\'s match was played on the Grandstand Court, only the third-largest of the show courts at the US Open. Lengthy rain delays during the week and water damage that shut down Louis Armstrong Stadium caused schedulers to put Stosur and Kerber on the smaller court and leave two men\'s semifinals and the Williams vs. Wozniacki semifinal at Arthur Ashe Stadium, the 23,000-seated center court.