No. 1 Naomi Osaka upset by Belinda Bencic in US Open round of 16

Another shocking upset rippled through Arthur Ashe Stadium on Monday, just hours after No. 1 ranked and defending champion Novak Djokovic was eliminated.

Naomi Osaka, who won her first Grand Slam on this stage a year ago, lost to Belinda Bencic 7-5, 6-4 in the round of 16.

Osaka, who advanced by beating close friend Coco Gauff, also won the 2019 Australian Open title. But while she displayed a punishing serve and groundstrokes during her 6-3, 6-0 win over Gauff, her game was off on Monday and her play was flat.

She came up lame late in the second set on service returns, favoring her wrapped left knee and seemed to be hampered in her movement.

Osaka used an ace and a blistering forehand return to hold serve at 5-4 in the second set, but Bencic came right back and held serve to take the match.

Bencic, the 13 seed, now has beaten Osaka three times this year.

“She’s a great player and I had to be at the top of my game. I’m really pleased with how I played and managed my nerves,” Bencic said in a televised interview after the match.

Explore more:  women's soccer ncaa rankings

Bencic will play Donna Vekic, who beat Julia Goerges in three sets.

Osaka’s loss is historic for another reason. This marks the first time since the 2017 Australian Open and just the fourth time in the Open era that the men’s and women’s No. 1 seeds have been ousted before the quarterfinals in a Grand Slam.

.Follow Heather Tucker on Twitter @HeatherR_Tucker.