@johnrisner gives #TeamUSATennis a 2-0 lead in the 2nd singles rubber of the @daviscuptennis World Group R1 clash 🆚 Serbia! Let's give John a 🇺🇸 for closing out that epic 6-4, 6-7, 6-3, 3-6, 7-6 battle! _ #tennis #daviscup #isner #ustennis #usasrb #usa #serbia #daviscuptennis #instatennis