Sunday Style: As expected, Bethanie Mattek-Sands is starting out 2018 dominating the fashion game. Send her a 🎾 if you love her style on and off the court! (📸: @matteksands) #usta #ustennis #bethaniematteksands #sundaystyle #tennis #protennis #instatennis #instasports #instafashion #instachic