WASHINGTON, DC - AUGUST 02: John Isner of the U.S. returns a forehand shot to Ruben Noah of U.S. during Day Six of the Citi Open at the Rock Creek Tennis Center on August 2, 2018 in Washington, DC. (Photo by Mitchell Layton/Getty Images)
WASHINGTON, DC - AUGUST 02: John Isner of the U.S. returns a forehand shot to Ruben Noah of U.S. during Day Six of the Citi Open at the Rock Creek Tennis Center on August 2, 2018 in Washington, DC. (Photo by Mitchell Layton/Getty Images)