John Isner reacts after a point against Philipp Kohlschreiber, of Germany, during the third round of the 2013 U.S. Open tennis tournament, Saturday, Aug. 31, 2013, in New York. (AP Photo/Darron Cummings)
John Isner celebrates after upsetting top seeded Novak Djokovic, from Serbia, 7-6 (5), 3-6, 7-5, in a quarterfinal match at the Western & Southern Open tennis tournament, Friday, Aug. 16, 2013, in Mason, Ohio. (AP Photo/Al Behrman)