Hunter Callahan defeated Alex Rybakov 7-5 7-5 in the USA F27 round of 16 on hard.
Callahan H. took it in straight sets.
Hunter Callahan beat Alex Rybakov 7-5 7-5. Umpiry, "Hunter Callahan vs Alex Rybakov — USA F27 Round of 16", https://umpiry.com/match/2017-08-07/callahan-vs-rybakov-usa-f27-r16?utm_source=cite (as of 7 August 2017).