Serena Williams was upset Victoria Azarenka in the US Open semifinals.<br />CNN reports that Williams is on a quest to win a record 24th Grand Slam title.<br />Azarenka rallied for a 1-6 6-3 6-3 victory on Thursday night in New York.<br />It's the first time Azarenka beat Williams in a major in 11 attempts.<br />Williams took a mid-game medical timeout for an Achilles tendon issue in the second game of the thirds set.
