|US Open 2019|
|Venue: Flushing Meadows, New York Dates: 26 Aug – 8 Sep|
|Coverage: Live text and BBC Radio 5 Live Sports Extra commentary on selected matches on the BBC Sport website and app. Click here for Live Guide.|
The Japanese, runner-up here in 2014, went two sets down before a brief fightback in a 6-2 6-4 2-6 6-3 defeat.
For Australian world number 38 De Minaur, one of the game’s rising stars, it was his first win over a top-10 player.
He will face Bulgarian Grigor Dimitrov or Poland’s Kamil Majchrzak next.