Alexander Zverev moved forward in the US Open. He faced Botic van de Zandschulp in the quarterfinal on September 9. The match continued for hours. It concluded after 2 a.m. At one point, Zverev called out at the umpire. The issue was a wrong ruling. It frustrated him. Despite that, he proceeded. In the end, he succeeded. After the match, he addressed the ATP Tour. He said, 'It was a match that I needed.' Karen Khachanov also proceeded. He advanced to the semifinals. His opponent, Blockx, ceased. So Khachanov triumphed by default.