Maria Sharapova was knocked out of the US Open in the fourth round on Monday, losing 6-4, 6-3 to Spanish birthday girl Carla Suarez Navarro who inflicted the Russian's first ever night-time loss at the tournament.
Naomi Osaka reached her first grand slam quarter-final with victory over fellow 20-year-old Aryna Sabalenka.
She made the fourth round at the US Open a year ago in her first Slam since her return, the third round in Australia in January and quarter-finals in Paris before a first round exit at Wimbledon in July. This is the way that I can play really good tennis.
The Spaniard will next play last year's runner-up Madison Keys for a place in the semifinals. "I really enjoyed this crowd, this incredible night session", Suárez Navarro said.
Suarez Navarro celebrated her 30th birthday in style, the straight-sets win ending Sharapova's streak of 22 consecutive victories in night matches on Arthur Ashe Stadium.
Osaka felt her extra history on the grand slam stage helped, saying: "I was the player with more experience, which is very odd for me to say".
Five-times Grand Slam champion Sharapova paid the price for 38 unforced errors and won less than half of her first serve points while committing eight double faults.
'I think that's a lot tougher than being 31 years old and having the opportunity to do whatever I want in my life'.
Suarez Navarro completed a convincing 6-4 6-3 victory to come back into the last 8 at Flushing Meadows after five years. Osaka said Sabalenka's blistering serve had been a key challenge to overcome toward the end of the match. She forced me to make mistakes.
Novak Djokovic did his part Monday at the US Open, punching his ticket into the quarterfinal round with a 6-3, 6-4, 6-3 win over unseeded Joao Sosa.
The first Portuguese player to reach the fourth round of any grand slam, the 68th ranked Sousa never looked a threat to progress any further as his magical US Open run came to an end.
"I hesitated to move forward".
But, thanks to an insane rally, she quickly tied the set back up.
"When I was a break down in the final set I thought I would even break a leg if needed so I could get to every ball". I was playing also previous year same day against Venus Williams, and I lost.
She was beaten by world number 12 Garbine Muguruza 6-2 6-1 in the last eight at the French Open this year in a one-sided match.
Osaka next faces Ukraine's Lesia Tsurenko, who struggled badly with the heat on the open Grandstand court against Marketa Vondrousova but battled from a set down to win 6-7 (3/7) 7-5 6-2.
Sharapova dropped serve in the fifth game of the second set and couldn't recover to push the match into a third set.
Keys has been solid in NY, having dropped a single set through four matches, and turned it up a notch against her 29th-seeded opponent as she lost only 10 points on serve during a 76-minute match in which she was broken once.