STARS Petra Kvitova beat Victoria Azarenka 7-5 4-6 6-3 to win the TEB BNP Paribas WTA Championships in Istanbul, Turkey Jo-Wilfried Tsonga beat Juan Martin del Potro 6-7 (5) 6-3 6-4 to win the Erste Bank Open in Vienna, Austria Marin Cilic beat Janko Tipsarevic 6-3 3-6 6-2 to win the St. Petersburg Open in […]