Instead, his older brother, Mischa, is the last Zverev standing after he beat Benoit Paire, 6-3, 6-2, 3-6, 6-7 (3), 7-5, to reach the third round.
Fifth-seeded Marin Cilic, the 2014 United States Open champion, is now the highest remaining seed in the bottom half of the draw.
On a night when the tournament lost one rising star, another one grew brighter as 18-year-old Denis Shapovalov of Canada ousted eighth-seeded Jo-Wilfried Tsonga, 6-4, 6-4, 7-6 (3), in a night match at Arthur Ashe Stadium. Shapovalov upset the top-ranked Rafael Nadal at the Rogers Cup in Montreal this month during a run to the semifinals. Shapovalov, playing in his first United States Open, will meet Kyle Edmund of Britain in the third round.