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 yelled at the umpire. The issue was a poor decision. It frustrated him. Despite that, he continued. In the end, he won. After the match, he talked with the ATP Tour. He said, 'It was a match that I needed.' Karen Khachanov also moved on. He advanced to the semifinals. His opponent, Blockx, quit. So Khachanov triumphed by default.