Australian Nick Kyrgios is out of the US Open after he was forced to retire from his third round match against Illya Marchenko due to a hip injury.
Kyrgios, who won the first set, began to feel hampered by the injury during the second set.
He had received treatment for the injury during his first two rounds of the tournament.
The 21-year-old trailed two sets to one, 4-6, 6-4, 6-1, when he retired from the match.
It was Kyrgios' first loss in 21 matches to unseeded opponents at grand slam events.
“It's tough. I don't like to retire. It's probably like the second or third time I've done it,” Kyrgios said post match.
“It's never easy, of course. I've got a lot of belief in my game to still win matches when I'm not feeling great.
“To be fair, my hip was bothering me my first two matches and I got through. I guess it was just a matter of time.
“My physio has been helping me all week. I've been trying to fix it all week. But it's the whole year leading up to it with the whole schedule.