see more

AUCKLAND, NEW ZEALAND - JANUARY 12: John Isner of the USA plays a forehand during his mens singles match against Steve Johnson of the USA during the ASB Classic on January 12, 2017 in Auckland, New Zealand. (Photo by Phil Walter/Getty Images)

AUCKLAND, NEW ZEALAND - JANUARY 12:  John Isner of the USA plays a forehand during his mens singles match against Steve Johnson of the USA during the ASB Classic on January 12, 2017 in Auckland, New Zealand.  (Photo by Phil Walter/Getty Images)