Marin Cilic suffered a shock third-round loss at the US Open as teenager Denis Shapovalov continued his run in New York.
Cilic's surprise defeat at the hands of Diego Schwartzman means there will be a first-time grand slam finalist in the men's draw.
Shapovalov, 18, remained on track to potentially grab the chance after Kyle Edmund retired during their clash, which the Canadian was leading.
Meanwhile, Mischa Zverev was too good for John Isner and Borna Coric exited, while seeds Sam Querrey and Lucas Pouille reached the last 16.
CILIC SLUMPS TO LOSS
With Roger Federer and Rafael Nadal on the other side of the draw, fifth seed Cilic was the highest remaining seed in the bottom half - until Friday.
The 2014 champion went down to Schwartzman 4-6 7-5 7-5 6-4 to make his earliest exit since 2011 at Flushing Meadows.
Schwartzman, into the fourth round of a major for the first time, next faces Pouille after the French 16th seed overcame Mikhail Kukushkin 2-6 6-3 6-4 6-4.
-- US Open Tennis (@usopen) September 1, 2017
The teenager is playing in the main draw of a major for just the second time, and his run continued as Edmund retired with a neck injury with Shapovalov leading 3-6 6-3 6-3 1-0.
It was in a match against the Brit that Shapovalov had an infamous moment earlier this year, when he smashed a ball and hit a chair umpire in the eye in the Davis Cup.
But he has a chance to make a name for himself for the right reasons, with Pablo Carreno Busta awaiting him in the fourth round after the Spaniard's 6-3 6-4 6-3 victory over Nicolas Mahut.
Shapovalov became the youngest man to reach the fourth round at the US Open since Michael Chang in 1989.
ZVEREV TOO GOOD FOR ISNER AS QUERREY ADVANCES
For the third time this year, Zverev beat Isner - claiming a 6-4 6-3 7-6 (7-5) victory over the American.
The German will face Querrey after the American 17th seed overcame Radu Albot 4-6 6-2 6-4 6-4.
The other fourth-round clash in the bottom half of the draw will be between Paolo Lorenzi and Kevin Anderson after their respective wins over Thomas Fabbiano and Coric.