Focus level: @sloanestephens Sloane is through to R3 of the #USOpen with a come-from-behind 4-6 7-5 6-2 win over Kalinina. Next up for the defending champ: a HUGE match vs. 🇧🇾 Azarenka. #tennis #sloanestephens #stephens #sloane #usopen #builtforglory #instatennis