Victoria Azarenka advanced to her second straight U. S. Open tennis final Friday, beating Flavia Pennetta 6-4, 6-2, in a nervous, mistake filled semi final. The players combined to hold serve in only five of 18 games. The second seeded Azarenka, the Australian Open champ in 2012 and 2013, improved to a tour best 31-1 on hard courts this year. She is trying to become the first person to win the Australian and U. S. Opens in the same year since Martina Hingis in 1997. Azarenka meets either Serena Williams or Li Na in the final.