Maria Sharapova sets up final match with Serena Williams at WTA Championships . She has lost to Williams in last year , but beat her in the 2004 final . Sharapova defeats world No . 1 Victoria Azarenka in Saturday 's second semifinal . This is the kind of tournament where you have to be fit every match to win . Williams cruised into her fifth final , beating fourth - seed Agnieszka Radwanska .
Maria Sharapova sets up final match with Serena Williams at WTA Championships . She has lost to Williams in last year , but beat her in the 2004 final . Sharapova defeats world No . 1 Victoria Azarenka in Saturday 's second semifinal . Williams cruised into her fifth final , beating fourth - seed Agnieszka Radwanska .