Kyle Edmund's US Open run ended in tears when he retired with a neck injury in the fourth set of his third-round match against Denis Shapovalov.
The 22-year-old, Britain's lone singles representative in the last 32, won the first set against 18-year-old Canadian prodigy Shapovalov at Arthur Ashe Stadium.
But Shapovalov fought back to level and Edmund's chance went when he appeared to hurt his neck in the fifth game of the third set.
He received three bouts of treatment but was clearly hampered and did not win another game before pulling the plug with Shapovalov leading 3-6 6-3 6-3 1-0.
It was Edmund's 10th match in 14 days after reaching the semi-finals of the Winston-Salem Open and his heavy schedule perhaps caught up him.
Shapovalov, meanwhile, becomes the youngest man to reach the fourth round of a grand slam since Marat Safin at the French Open in 1998 and has a great opportunity to go further in a wide open section of the draw.