Three tiebreaks. One 🇺🇸 winner. @johnisner slams 32 aces to win a 6-7, 7-6, 7-6 marathon over P. Cuevas in R3 of the @mutuamadridopen! Give Big John some 👏 for stepping up when it matters most! _ #usta #ustennis #johnisner #mmopen18 #atp #tennis #protennis #instatennis #instasports