Dominik Koepfer defeated Ryan Harrison 6-1 6-1 in the US Open qualifying round of 128 on hard. The upset overturned the form book — Ryan Harrison came in defending last year's round of 128, but Dominik Koepfer had been the form player, winning 4 of their last 7 on hard.
Koepfer D. took it in straight sets.
Dominik Koepfer beat Ryan Harrison 6-1 6-1. Umpiry, "Dominik Koepfer vs Ryan Harrison — US Open Qualifying Round of 128", https://umpiry.com/match/2019-08-19/harrison-vs-koepfer-us-open-q128?utm_source=cite (as of 19 August 2019).