Knee injury hampers Osaka as women's top seed follows Djokovic out of US Open
Top seed and defending champion Naomi Osaka crashed out of the US Open in the fourth round after a straight-sets defeat by Belinda Bencic.
Osaka has been carrying a knee injury and called the trainer and a medic on midway through the second set, although she was able to carry on without receiving any treatment.
However, the 21-year-old from Japan was beaten 7-5, 6-4 by the Swiss 13th seed. Her defeat came just a day after men's champion Novak Djokovic also bowed out after retiring at two sets down to Stan Wawrinka.
Osaka was cheered to the rafters as she trudged off court, a crowd favourite now after the way she consoled American youngster Coco Gauff following their match on Saturday night.
It was a third straight win for Bencic over Osaka this year, and she said: "The challenge cannot be bigger against Naomi, she won this title last year. I'm really pleased with my game and how I handled my nerves. I tried taking the serve early and trying to anticipate, because she has a lot of power.
"I was in the stadium watching the (Gauff) match and thought it was an unbelievable moment for tennis. What Naomi did is what a true champion would do."
Bencic will play Donna Vekic in the quarter-final after the Croatian came from a set down to beat Julia Goerges of Germany. Goerges had a match point in the second set but ended up losing 6-7 (5) 7-5 6-3.
Djokovic succumbed to a shoulder injury as his US title defence came to an end against Stan Wawrinka.
The crowd on Arthur Ashe were stunned when the world No 1 approached Wawrinka and embraced him while trailing 6-4, 7-5, 2-1. Djokovic has been bothered by a left shoulder injury all week, although it was not apparent during the opening two sets with Wawrinka reprising the sort of form which made him the champion in 2016.
But the Serbian took a medical time-out after dropping the second set, and three games into the third he decided enough was enough.
"I congratulate Stan. He's a great player. I really wish him all the best the rest of the tournament. I don't want to talk about my injuries. I said that in the past. I'm sticking to that."
The result means Wawrinka will face fifth seed Daniil Medvedev in the quarter-finals, while the draw has opened up for Roger Federer, who was in imperious form against David Goffin and had been expected to run into Djokovic in the last four.
Earlier, Medvedev revelled in his role as the villain of the tournament after beating Dominik Koepfer to reach the quarter-finals.
The Russian, who caused a stir by sticking his middle finger up at the crowd in a 'visible obscenity' two nights earlier, was jeered. He won 3-6, 6-3, 6-2, 7-6 (2), before goading the crowd again with his celebration.