Quarter-final spots are on the line in Houston! John Isner faces Frances Tiafoe, Taylor Fritz battles Cristian Garin and Reilly Opelka meets Gijs Brouwer. SUBSCRIBE to our channel for the best ATP tennis videos and tennis highlights: https://www.youtube.com/tennistv?sub_confirmation=1 Watch official ATP tennis streams from every tournament: http://tnn.is/YouTube Tennis TV is the OFFICIAL live streaming service of the ATP Tour. Tennis TV features live streaming and video on demand of ATP tennis matches in full on PC, Mac, mobile & tablet apps on iOS & Android. Download the app to stream on your device: http://tnn.is/YouTube Plus Tennis TV is also available to stream tennis on your TV on Apple TV, Roku, Amazon Fire TV, Samsung Smart TV, LG Smart TV, Android TV, PlayStation 4, Xbox One and Chromecast. To enquire about licensing ATP Tour footage contact IMG Replay: http://imgreplay.com/client/atp_media #tennis #tennistv #sports