Heather Watson defeated Coco Gauff 6-4 6-1 in the US Open qualifying round of 128 on hard. The upset overturned the form book — Coco Gauff came in ranked #4.
Watson H. took it in straight sets.
Heather Watson beat Coco Gauff 6-4 6-1. Umpiry, "Heather Watson vs Coco Gauff — US Open Qualifying Round of 128", https://umpiry.com/match/2018-08-22/gauff-vs-watson-us-open-q128?utm_source=cite (as of 22 August 2018).