Karen Khachanov

The German became the first No. 1 seed ever to be dragged into five sets in the first two rounds of a Grand Slam. Eventually, he survived against Halys, Gauff also advanced, while Auger-Aliassime and De Minaur were eliminated.

The world number 4 was eliminated in the second round of the US Open after a loss to Khachanov, and revealed he suffered from dizziness and vision problems: "I've never felt like this". The Canadian will undergo tests in an attempt to understand what happened to him.