Already a sporting icon, Osaka's fight for equality has focussed even more attention on her
A factor that could work in the Belgian's favour is the unprecedented nature of this year's Grand Slam.
Big-serving Canadian Milos Raonic fired 19 aces to topple Sam Querrey 6-4, 6-4 and set up a second-round clash with either Dan Evans or Russian 10th seed Andrey Rublev.
Halep finds groove to reach Prague semi-finals.
In a rematch of their tumultuous 2018 US Open decider, Osaka underlined her status as the new queen of women's tennis and soaked up the cheers from the Rod Laver Arena crowd as fans returned to the Grand Slam after a five-day lockdown.
Venus Williams stands in the way of younger sister Serena's bid for a calendar-year Grand Slam after reaching the quarter-finals with a 6-2, 6-1 rout of Estonian teenager Anett Kontaveit on Sunday.
The Serena Williams show continued at the US Open as the world number one moved a step closer to a calendar Grand Slam on Wednesday, while Mardy Fish took a final Flushing Meadows bow as the curtain came down on the American's career.
However, the 30-year-old Russia belied her own self-doubt with an impressive three-set win over the Romanian to thrust the former world number one back into the spotlight as the toast of the Big Apple.
Rafael Nadal was at his awe-inspiring best as he recovered from a first set wobble to crush Juan Martin del Potro 4-6, 6-0, 6-3, 6-2 in the US Open semi-finals on Friday and move within reach of a 16th Grand Slam title.
Man of many faces, Medvedev now a Grand Slam finalist
In the decider, Berrettini broke twice for a 4-2 lead but a rejuvenated Monfils dug deep and raced around the court to fight off three match points to force a final-set tiebreak. But it was Berrettini who leaned on his powerful serve to prevail and become the fourth Italian man to reach a Grand Slam semi-final in the Open Era.
'I understand it's a show, but under the roof we need to be a little bit more strict about the noise. All the noise stays inside, and this is difficult.'
"For me, right now I have this feeling of sadness," said Osaka.
As the fans head toward Flushing Meadows, tennis stars gear up with ground-breaking styles to rule the courts.
Tomic has withdrawn from his last four tournaments, pushing his ranking to depths that will require him to battle on lower-tier tours or beg for wildcards from tournament organisers next year.
'I don't mind when he misbehaves. Obviously, I don't like the bad language. It's just when he doesn't try to play tennis, when he doesn't try to win then I think the umpire needs to step in. I think in this situation, default him on the spot, rather than suspend him'
World number eight Williams, who captured the first of her six US Open titles two years before her 17-year-old opponent was born, spent the first half of the match trying to find her rhythm but when she did she was off to the races.
Factbox on Rafael Nadal, who beat Dominic Thiem 6-4, 6-3, 6-2 to win his 11th French Open title on Sunday:
World number one Naomi Osaka will "probably" defend her US Open title, even if it means defying her doctor's orders.
Kevin Anderson spoiled the American party at the US Open when the big-serving South African beat local favourite Sam Querrey 7-6(5), 6-7(9), 6-3, 7-6(7) to reach his first Grand Slam semi-final on Tuesday.
'The governing bodies, especially Grand Slams, need to allocate enough funds to support lower-ranked players, low-level tournaments, futures, challengers and I believe there is enough funds for those too.'
'It's always going to be ... in the years to come, 'oh, you know that guy won a US Open in 2020 without fans'. I don't think it's going to have that weight... It wouldn't be the best scenario.'
IMAGES from matches on Day 4 of the US Open at Flushing Meadows in New York on Thursday.
Images from the third day at the US Open, the final Grand Slam tournament of the year, in New York, on Wednesday:
IMAGES from Day 3 of the US Open in New York on Wednesday.
If the Board of Control for Cricket in India (BCCI) decides to follow the recommendations on reforms suggested by the Justice RM Lodha committee, one could soon find stadiums in Pune, Nagpur, and Rajkot hosting Indian hockey team's 'Test' matches or tennis team's Davis Cup games.
Images from Day 8 of the 2021 US Open in New York on Monday.
The 17th seed has been in no-nonsense mood so far in Melbourne, moving through the rounds with the minimum of fanfare, but faces her biggest test against the German.
Coco Vandeweghe was in two minds whether to answer the call when an unknown number with a strange international dialling code popped up on her telephone last year.
A golden moment for Australian Ashleigh Barty and American CoCo Vandeweghe was tinged with disappointment when tournament officials did not let them speak to the crowd after winning the U.S. Open women's doubles final on Sunday.
More shocking than his departure was the manner of the 3-6, 7-5, 7-6 (7), 7-6,(3) loss to the Australian, with Federer simply wilting in the suffocating humidity and exiting a Grand Slam before the quarter-finals for just the fifth time since 2004.
On Saturday, the young guns showed no signs of breaking the stranglehold of the three men who collectively own 50 Grand Slam titles and also split the season's first three majors.
Roger Federer conceded he has changed some things because of his age.
Top seed Novak Djokovic was tested by net-charging Spaniard Feliciano Lopez in a duel of volleys and passing shots before booking a berth in the semi-finals of the US Open in the wee hours of Wednesday.
Fourth seed Kei Nishikori's hopes of making another magical U.S. Open run came to a quick end on Monday as last year's runner-up fell at the first hurdle, falling 6-4, 3-6, 4-6, 7-6 (6), 6-4 to Frenchman Benoit Paire.
World number ones Serena Williams, aiming to complete the first calendar-year Grand Slam in 27 years, and Novak Djokovic have been named the top seeds for the US Open championships starting on Monday in New York.
Verdasco questions French Open COVID-19 testing protocols after withdrawal
Roberta Vinci beat her opponent and the rain to storm into the quarter-finals of the US Open on Monday just before a thunderstorm forced play to be suspended.
Former champion Naomi Osaka is wearing a different facemask for each of her matches at the US Open this year.
The United States Tennis Association (USTA) will reveal plans to build a retractable roof over the centre court at Arthur Ashe Stadium as part of major changes to the U.S. Open venue in Flushing Meadows.